# 1 idal-Flow, Circulation, and Flushing Changes Caused

- 

# by Dredge and 

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### rnnn\A/II\..I I - .. _- • ........ '--" '--" L..o' .. ... "
Prepared in cooperation with the 

## u.s. Army Corps of Engineers and the Tampa Port Authority



## U . S. G EO lOG I CAL 5 U RV EY W ATE R-S U P PLY PAP ER 2282

## DEPARTMENT OF THE INTERIOR**~~~ ~~."** **l~~~** 

## DONALD PAUL HODEL, Secretary 

# !:.,,"y . -. i**.~~** -r-'" , -

# .'~ ;/1' 

# "':U

.**\~'.** ., : U 0 

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.... , ...... I**\\~** . .., .-. 1bJ U.,:). \...II:V LV\...I I Lf'\L ,:) U '" V I: ,

### ~~!.**'".Ll."~** 

## Dallas L. Peck Director .**~~.':."d: ~h3W** 

UNITED STATES GOVERNMENT PRINTING OFFICE: 1987 

### For sale 

### by the Books and Open-File Reports Section, U.S. Geological Survey, Federal Center, Box 25425, Denver, CO 80225 Ubrary of Congress Cataloging in Publication Data Goodwin, Carl R.
,,,., 'cArl h" nrArln
.. ",nn fill in**~.** 10. _:._••**I~"_~ ~ft""**  4l,**,~h:~~** , Tampa Bay, Florida. (U.S. Geological SUNey water-supply paper; 2282) Bibliography: p.**c,,~.** "f nn"" nn' I 1 1**~:2282** 1. Tides-Florida-Tampa Bay-Data proc/*lsing. 2. Tides-Florida-Tampa Bay-Mathematical models. 3. OCeanic circulation-Florida-Tampa Bay-Data processing. 4. OCeanic circulation-Florida-Tampa BayMathematical models. 5. Dredging-Florida-Tampa Bay. 6. Fills 

# _.' T___ I:t;', I I Ift:.<W'l c......'; Ar""''' r",rfte. nf**Engineer~:'** II. Tampa Port Auth()'rity. III. Title. IV. Series. GC334.G66 1987 551.46'34 84-600408

# CONTENTS Abstract 

### 1 Introduction 

### 1 t'urpose ana scope 2 Methodology 

### 2



# - .C "+
.. A ••**,~~~** 

# ., OJ -.-- 

# - Previous studies 

### 9 Acknowledgments 

### 10 Description of computer simulation system 

### 10 uovemmg equations lU Numerical procedures 

### 11 Tnnllt 1" 

## . QDerations 

### 13 Model development and application 

### 13 Bottom configuration 

### 13 DounDary conDItions !() Bottom boundary 

### 16 Shorelines and tributary streams 

### 16 Seaward boundarv 17 Water-surface boundary 

### 19 Initial conditions 

### 21 UDal sIage ana tIaat current :.H ,.., 

## ...... 

# .... Calibration and verification 

### 22 Tidal stalle 

### 22 Tidal current 

### 23 Dispersion 

### 28 Application to 1880, 1972, and 1985 levels of development 

### 32
A. ... ... J" Boundary conditions 

### 32 Initial conditions 

### 32 Model results and analysis 

### 35 Methods 

### 35 Vector computations 

### 35



## .... 

# ..... a. 

# - lIlCl",,, JJ Longitudinal summary 

### 35 Water transport 

### 37 Flood and ebb water transport 

### 37 1'100a and ebb water-transport differences for 1880, 1972, and 1985 

### 46 D 'A .1

...

### '" 

# ....". 

# ,. ..,"" Residual water-transport differences for 1880, 1972, and 1985 

### 51 Constituent transport 

### 63 Flood and ebb constituent transport 

### 64 t'Jooa and ebb constituent-transport differences for 1880, 1972, and 1985 

### 71 n '..I. .,If Resirlll::ll 

# - fnr 1 RRfl 1 Q7' and 1985 77 Contents III

### Summary 

### 84 Selected references 

### 86 Glossary of selected terms 

### 87 Abbreviations and conversion factors 

### 88 FIGURES 1. Location map of Tampa Bay study area 

### 3 

# " r. .. ",nh "nrl 

## .. nf tun;"" 1 t;rI
.. " 

# -.**-~** 

### .

# . in Tampa Bay 

### 4 3. Map showing locations where physical changes were made to Tampa Bay between 1880 and 1972 

### 5 4. 

### Map snowmg lOCatIOnS 01 

### major suoareas ana areas 01 

### pnyslcal cnange projected for Tampa Bay between 1972 and 1985 6 

# "_7 

# ..... 5. Finite-difference scheme for computer simulation model 

### 12 6. Relation of programs, files, input, and output for the simulation modeling system 

### 14 I.**~al1oralion** 

### ana verhicadon SLepS in mOUel uevelopmem 1;' 

### 8. Map showing location of tidal stage and tidal current measuring sites <Inri <Inri Inn17-t..rm s.itl"S in ,,1 nnH 

### Bay 

### 18 9-12. Graphs showing: 9. Comparison of observed tidal stage in the Gulf of Mexico and at ron ue "OLO insiue me mouLII 01 1 

### ampa Day 1::1 

### 10. Comparison of observed tidal stage in the Gulf of Mexico with tirl",1 d",
.... h" ,,<:in
.. ,...n",,_ ., 

## .,n**-~** "**-~** 

# . 11. Comparison of computed tidal stage in the Gulf of Mexico with observed tides at Fort De Soto during model calibration and verification periods 

### 21 w 

### ina speea ana 

# .. U:. 

### aunng anu periods 

### 22 13-15. Graphs of observed and computed tidal stage at selected sites in Tampa Bay: 

### 13. During calibration period 

### 24 14. During first verification period 

### 25 1 :>. 

### uuring seconu verhicadon pcriou 

## .u ,r**~.** 

### ". ,. 

### "

# .. .v. v. 

# .... 

# ...... 

# .. 17. Graphs of observed and computed tidal current speed and direction at selected sites in Tampa Bay during first verification period 

### 29 18. Graphs of observed and computed tidal current speed and direction at selected sites in Tampa Bay during second verification period 

### 30

, 

## .. 1::1.**11l1i:l~l;** Ul
.... "'... ,.)' lJ1Ull1l; 111 .l i:lll1lJi:l Di:lY i:lllU Ul**:~nnA n~r1**  • .,**~1"~A** 't1 

# ..". OJ .. 

### 20. Graph of tidal stage and tidal current used during turbidity plume simulation 

### 32 21. Diagrams of shape of simulated turbidity plume at selected times following start of turbidity generation 

### 33 22. Graph of repeating, 24-hour tide used as boundary condition for model


# .. 'tLl 

# . 23. Map showing phosphorus distribution in Tampa Bay, July 1975 

### 36 24. Diagram showing computations for vector addition and subtraction 

### 37 25. Diagram showing computations for average flood- or ebb-transport vector ana tor reslaual-transport vector 38 

### 26. Map showing longitudinal summary lines and circulation zones of D",,, 'to -r 

# -.
IV Contents27-29. Maps showinp; water-transport pattern durintl tvnical floodtide in Tampa Bay for: 27. 1880 level of development 

### 40 28. 1972 level of development 

### 41 ..,n I**no~ 1~**  .._1 _J.' • 

## ""**~-** 30-32. Maps showing water-transport pattern during typical ebbtide in Tampa Bay for: 30. 1880 level of development 

### 43 31. 1972 level of development 

### 44 32. 1985 level of development 

### 45 'l'L'l1;; l\Jf**"n~"** ;n ul"t"r**;~** 

### - Dn**4'~** •• -or**-~** -r 

### 0" OJ 33. Tvnical floodtide between 1880 and 1972**Ipvpl~** nf development 

### 47 34. Typical floodtide between 1972 and 1985 levels of oevelOpmem**,,~** 35. Typical ebbtide between 1880 and 1972 levels of development 

### 50 'll;; 

## - 107..,**n~r1 10Q~** **1~** ..**ol~ ~4'**  C1 r 37. Graph showinp; water transport**alom~** lontlitudinal summarY lines durintl typical floodtide and ebbtide in Tampa Bay for 1880, 1972, and 1985 levels of development 

### 52



# - lVlaps snowing resioual waler-IranSport pattern m 1 ampa lSay ror: ",o,-,+u. 38. 1880 level of development 

### 54 39. 1972 level of development 

### 55 40. 1985 level of development 

### 56 41. Map showing representative residual water-transport pattern at the entrance to Tampa Bay for 1972 level of development 

### 57 "'ZJZ. Map snowmg cnanges m resIaua! water transport m Tampa Bay 1001\ ._-1 1 

### ""''''l 1.J.'**~n.** 

# .**.~ ~oo~**  ••**.~~.~ ~.** **~~** "'7 43. Map showing changes in residual water transport in Tampa Bay between 1972 and 1985 levels of develonment 

### 60 44. Graph of average tributary streamflow and tide-induced circulation in Tampa Bay along longitudinal summary lines for 1880, 1972, and 1985 levels of development 

### 62**A~** A.., 

# .. ,,-- ••• M 

## . .,**'~p~** "0 r**~L)'}JI""U** HI Tampa Bay for: 45. 1880 level of development 65 

### 46. 1972 level of development 66 47. 1985 level of development 

### 67 48-50. Maps showing constituent-transport pattern during typical ebbtide in D_. J.'••**'p~** 'J**.~** •• 48. 1880 level of development 

### 68 49. 1972 level of development 

### 69 50. 1985 level of development 

### 70 5 I-54. Maps showmg Changes m constItuent transport m Tampa Bay for: 51. Typical floodtide between 1880 and 1972 levels of


# . . .,,, 52. Typical floodtide between 1972 and 1985 levels of development 

### 73 53. Typical ebbtide between 1880 and 1972 levels of development 

### 75 

## '4. TypIcal ebbtIae between I**~7:l** ana 1985 levels of development 

### 76 55. Graph showing constituent transport along longitudinal summary lines r1 .. r;nlT
...... ;,..,,1 ., "nrl**'.I'~** 'T'n

__n D

__**4'~_** 1001\ In..,..,**n~-I** '0 ·r 

# ... OJ 

### , , 1985 levels of develonment 

### 77 56-58. Maps showing residual constituent-transport pattern in Tampa Bay for: 56. 1880 level of development 

### 78 

# 'I. I**~'j:l** level or development 79
Contents V

### 58. 1985 level of development 

### 80 59. Map showing changes in residual constituent transport in Tampa Bay between 1880 anCfT97ZTevers ot C1evelopment 81 

### 60. Map showing changes in residual constituent transport in Tampa Bay

• n"""

_ .oJ •**no~** ,_. __,**~~** , 01 £J'_ ....... £J ,oJ 

### 61. Graph showing tide-induced and streamflow flushing of example constituent along longitudinal summary line from lower Tampa Bay to Hillsborough Bay for 1880, 1972, and 1985 levels of development 

### 84 TABLES



### 1. Physical changes made in Tampa Bay since 1880 

### 7 2. Physical characteristics of major subareas of Tampa Bay and of Tampa Bay overall for 1880, 1972, and projected 1985 levels of development 

### 8



# - ".,
.. n .... ;J. ".," i1UUUi11 vI**.~** £ ......y .. ...... ... 

### 4. Calibration and verification time periods and field data availability for tidal sta2e and current observations in Tampa Bay, 1972 

### 22 5. Information summary for tidal stage stations in Tampa Bay 23 

### 6. Standard error of tidal stage in Tampa Bay for calibration and verification periods 

### 23



# - .. " 

## .**~.,** • 'T". n. 

## "'

# .. I. VI uu .... ..**~~** ... £ ..... 1'
..**~"J** - 

### 8. Standard error of tidal current speed and direction in Tampa Bay for verification periods 

### 31 9. Stage, first difference, and second difference of repeating, 24-hour tide in Tampa Bay used as boundary condition for model application 

### 34 10. Water transport and direction during typical floodtide at selected sites in
" Inn'" ,,_,. •**no~** ,. .," 

### "L J "IUy" u .. IVI JUUV, .......... , .JU-'**.~ ,~.~**  v. .v 11 W!ltpr !Inti··· ti'lrinl1**tvni~al** • .• at l:itf"l: in 

### Tampa Bay for 1880, 1972, and 1985 levels of development 

### 49 12. Flood and ebb water transport and percentage changes in Tampa Bay for 1880, 1972, and 1985 levels of development 

### 53 13. Residual water transport and direction at selected sites in Tampa Bay for 1880, 1972, and 1985 levels of development 

### 58 1A A"...."n... :...1 .._' !Inti fnr P!lt"h t";rt"111!1_ 

### -., 

# . tion zone in Tampa Bay for 1880, 1972, and 1985 levels of development 

### 62 15. Constituent transport and directIOn dunng typical tlooC1tiC1e at selected sites Inl 

### ampa Hay lor Tl5'W, T':ITZ', 

### ana 1'-0;,) 

### levelS or 0'1 

### 16. Constituent transport and direction during typical ebbtide at selected sites ;n R!lU fnr 1 SHUl 107') !Inti 1QRIii If"Vf"Il: nf ' , '71 

# -. 17. Flood and ebb constituent transport and percentage changes for 1880, 1972, and 1985 levels of development 

### 74 18. Residual constituent transport anC1 C1lrectlon at selecteC1 SItes In 

### Tampa Hay lor 100U,**l'-f~,** 

### ana 1'-0;) 

### levelS vi OJ 

### 19. Tide-induced flushing and percentage changes in Tampa Bay for 1880, 1 Q7? !Inti 1QR'ii lpv"l" nf H4

VI Contents

# Tidal-Flow, Circulation, and Flushing Changes r""",r"rJ ho.I r'\
.. 

### "rJ"."
........ ,J 

### c:II :_ ,""UUJ'-'U 

## uy L.",--u5'-- allu I III III 

# Tampa Bav, Florida By Carl R. Goodwi n Abstract Model results show that the bay can be functionally sub- .J: '.J .J
. .**.~.. T~**  .L physical '0' . .J• 

# -' Tampa Bay, Florida, underwent extensive trances to Tamoa Bav and the maior bav subunits**HillsboroUl~h** cnanges oeTweenr tstsU and I '::J/L oecause ot construction ot Bay and Old Tampa Bay, have several times greater average causeways, islands, channels, and shoreline fills. These changes circulation than do adjacent and more landward zones. Cir- resulted in a progressive reduction in the auantitv oftidal water • ,-. .L • that enters and leaves the bay. Dredging and filling also changed**o",,~,a"T** 'v L"" '-' U**.~** LV '" head of Hillsborough and Old Tampa Bays, with a striking ex- the magnitude and direction of tidal flows in large parts of the ception in zone 3 in mid-Tampa Bay. This lO-mile section of bay. the bay has significantly lower average circulation than that A**two-dimen~ion;ll** finitp- '
. , VI , LV'**,<::~,** Iy Ivr**,~VUV. II<::~<::V**  model was used to simulate flood, ebb, and residual transport tion is thought to be a circulation constriction that reduces the of both water and a dissolved constituent for the physical con- potential transport of dissolved and suspended constituents.**V;L;V'~** L"aL ",,;,,"u' lelllIl-'eI VelY VU';1I5 IOOU drlU 1:1/, dilU Circulation in the constricted section was computed as for the "; thAt ;lrp likpl\' to pxiq in 1 QRI; Tl
. IIdV "5 U 1-'<::' ,,<:: " I UI<::U5<:: ellIU lill**Lurl~UUL** and verified model was used to hindcast water- and constituent- tion between 1880 and 1972. An additional increase of 21 per- transport changes caused by construction in the bay between cent, due to the Federal dredging project, is calculated. With

VVVelliV I :7i
....**l~** IIvuel**Wd~ u~eu** **ell~V** TO these increases, this zone acts as less of a constriction than it that can be expected to occur as a result of a major Federal did in 1880. This and other circulation increases may have con- dredging project scheduled for completion in 1985. tributed to increased bay salinity and to more rapid flushing The model forecasted transport changes caused by the of constituents from the bav to the Gulf of Mexico. reaeral areaging project to oe mucn less areally extensive man the corresponding transport changes caused by construction in Tampa Bay between 1880 and 1972. Dredging-caused changes of more than 50 percent in flood and ebb transport 11"1 I .11'-'1"1 were computea to occur over onlY ts or '::J square miles ot tne Dredge, fill, and other construction activities have bay's 390-square-mile surface area between 1972 and 1985. The model com outed that construction between 1880 and 1972 created many physical features in Tampa Bay that were caused changes of similar magnitude over 58 square miles of not present before about 1880. These features include tens the bay. Dredging-caused changes of more than 50 percent of miles of ship channels, many square miles of islands**:~** .**~o** 

## . 

# . .
.-**J~ J'1~~'-**  i:l,UU 

# - .' '**~HC~,** luur lUi:l,- miles of the bav between 1972 and 1985. According: to the**~~.** "",A +1,,,+ N""'"
..**t.~ 1..~.** **~",r1** J

.." -" OJ' model simulation, construction between 1880 and 1972 caused numerous residential and commercial shoreline landfills. changes of similar magnitude over 167 square miles. Most construction occurred between 1880 and 1972, and ,-. peak activity occurred in the 1950's and 1960's. Before**v,~w "~LV'** **,~~.** LOU'
- 'vu""" patterns. The patterns consist of a series of about 20 interconthis study, the cumulative impacts of these features on nected circulatory features that range in diameter from 1 to movement of water and waterborne constituents in the 6 miles. Dredging- and construction-caused changes in size, h"" ","'r'" nnt \11",11 • "",A'**~f'** " ..,..**I-'V~"'V** ""al-''', elIIU**"~""LT** VI ",<:: 'y**leellUle~** 

### " tide-induced circulation and flushing throughout most of the future physical changes could not be anticipated or combay. As a result of past and projected physical changes, the pared with past changes. bay can and will more rapidly transfer waterborne constituents A Federal dredging projectto widen and deepen the lIlell rlelve lelllUWara**~uurces** IO me UUII OT Mexico. Lonverse- mam smp cnannel m lampa liay was startea m l'J/o. liy Iy, the bay can and will more rapidly transfer constituents that 1985, the anticipated end of the project, approximately have their source in the Gulf into the upper parts of the bay. '7{\ •• "A 3 nf h,,,, • ",HI h""", 1.. ,n .....**~,,"'A** "",A " ." Introduction 1

### adverse environmental effects. A need for predictive and comparative information on flow, circulation, and flushing was recognized. on the overall health and ecological stability ofestuaries. In eneral increases in 

### estuarine circulation result in more rapid net movement ofdissolved and suspended constituents from regions ofhigh concentration to regions oflow concentration. Changes in circulation in an estuary, tion and concentration levels ofall waterborne material. Lon -term chan es in man h sical chemical and biological properties of estuarine water can induce ecological shifts that may destroy natural checks and balances within estuaries that have evolved over many estuaries and 2 tidal-flow, circulation, and flushing changes in Tampa Bay due to dredge and fill.

(2) conditions that existed in 1972 before start ofthe reThe levels represent (1) conditions that existed in 1880 To meet study objectives, detailed hydrodynamic simulation models ofwater and constituent motion were the U.S. Geological Survey, initially in cooperation with the Tampa Port Authority and subsequently in cooperaimpact of dredge and fill projects on water circulation, as a means to help forecast the ecological shifts that might result, led to this study. The study was undertaken by



### Purpose and Scope cent ship-channel dredging, and (3) conditions that are expected to exist in 1985 after completion ofship-channel This study addresses the effects of dredge and fill on tidal flow, circulation, and flushing in Tampa Bay.

prior to a large Federal dredging project to widen and deepen the main ship channel in Tampa Bay); 3. to determine tidal-flow, circulation, and flushing c anges etween an cause Y e Federal dredging project; and and flushing changes caused by the Federal dredging project and all prior construction in Tampa Bay. The circulation mechanism investigated in this compared by using vector maps, vector-change maps, and circulation and flushing summary diagrams to determine the nature and degree of changes in tidal flow, circulation, and flushing among the 1880, 1972, and 1985 levels of development. Bay, effort was directed to develop a close match between (1) measured physical dimensions of the bay and their numerical representation in the model and (2) other measurable phenomena and corresponding model comof water levels were made at many sites along the bay's shoreline. The magnitude and direction oftidal currents were measured at several sites within the bay. Constituent motion, in the form of turbidity plumes, was obtained from satellite imagery. report is a tidal "pumpmg" action cause y mteractlOn between tidal flow and an irregular bottom configura-



# . . at the start of the cycle if tidal inflow (flood) and tidal outflow (ebb) patterns in an estuary are exactly the same and ifother flow-in ucmg mec anlsms are not operatmg. 

### Description of Study Area

2 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida..-_._ ••**~.** __ -- ""<\ \J \

TAMPA 

### T**HIGGIN~** \

### ~~~~~TIONAL \ '-- TAMPA 5\ ,/

.,,, Or'\A'
- \ oJ>. • HifjStwrou9h\.. ('( , J ....... 0

__ I V<.. oJV



# --v.1._
- .. \ 

# -J ."'7 

# ,...... \ 

# "- ('

## ~T."'pETERSBURG- ./ \ MaeDILL
........... INTERNATIONAL

### ~WEEDON 

# I1l AIR

### ~RCE '\ 

# ..7 \

\

# ~~_AI:\ 1,\ 

# f!/ BEND

... TAMPA /-- SA Y ST. PETERSBURG t!= AIRFIELDI L....Liffle

# ~tT**~\** 

# 'I // R •**~irports** IV \ \\ ;-

_ 0 Powerplants 

# I\KEY /**I~** 

# )**~"'- y~** 

# ,~ f'\.RBRADENTON

# 17 I I I I 

# 7 .. 11

# ~C:\**~'II'~' ~..L.-..L.-....I...-...L.-....J** **SARASOTA-~ADENTON** \

_ '.4 Mil**E~** ?7· ":1\(\' Figure 1. Location of Tampa Bay study area.

Introduction 3

### n Th o ulation ofthe three-county area in 1982 was approximately 1.6 million, with a growth rate of about 42,000 residents yearly since 1970 (Thompson, 1980). mp mil (Lewis and Whitman, 1985) and is the largest estuary in Florida. Its average depth is about 12 f1. The maximum depth, about 90 ft, is offthe northern tip ofEgmont Key at the mouth of Tampa Bay. The Tampa Bay area has a subtropical climate that Water motion is dominated b tides that t icall convey about 21, 3, and 5 billion ft3 

### ofwater during each flood and ebb cycle at the mouths of Tampa Bay, Hillsborough Bay, and Old Tampa Bay, respectively. The



## . ., 

### to the effects ofthe sun (diurnal) -one high and one low tide per day-and moon (semidiurnal)-two equal high and low tides per day

- is approximately equal. The result is a highly variable tide that exhibits predominantly diurnal characteristics on some days and semidiurnal charand Conover, 1981). More than half of the rainfall occurs from June through September, primarily from thunderstorms. Tributary inflow to Tampa Bay averages about unequal low tides each day (fig. 2). The physical dimensions ofTampa Bay have been altered many times since the late 1800's. Most changes have resulted from man's desire to develop and expand for motor vehicle transportation across the bay, to build waterfront residences, to construct power generating stamodified from Lewis and Whitman (1985), Goetz and

00 

### win , p. subareas ofTampa Bay (lower Tampa Bay, middle Tampa Bay, Old Tampa Bay, and Hillsborough Bay), as tions, and to develop recreational areas. Table 1 presents a summary of many of the physical changes that have occurred in the bay. Locations ofthe changes are shown

and biological processes before being flushed into the

u 0 eX1CO. 

### a variety of dissolved and suspended organic and inorganic constituents. Many constituents settle to the bottom ofthe bay. These constituents are subject to benthic



## . . These are distributed by water circulation throughout the bay. The dissolved constituents undergo various chemical 

### , municipal and industrial discharge, and runoff from adjacent urban and agricultural basins into the bay contain

Seasonal variations in freshwater runoff cause p.4). w ter-surface area of salinity and other constituents in bay waters (Goetz and Goodwin, 1980, p. 20). However, tide and wind actions combine to inhibit formation ofsalinity differences volume, and average depth of each major subarea for physical conditions in 1880, 1972, and 1985. The values are for a water-surface altitude equal to the National GeoWlt ept un er mos con 1 

### lons. e ay IS 

### predominantly well mixed vertically and has little densie lC e lca a um area of Tampa Bay shown in table 2 differs from that

. ause ofsmall difFigure 2. Diurnal and semidiurnal characteristics of typical tides in Tampa Bay. 4 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaFi ure 3. Locations wh 

# ,

o EXPLANATION

SHORELINE DURING 1880 PHYSICAL CHANGES THROUGH 1972

------------ SUBMERGED SPOIL DISPOSAL

4 5 MILE 

### I I

Introduction 56 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida EXPLANATION

- - - - SUBAREA BOUNDARY 67 INDEX NUMBER FOR SITE OF TABLE 1) ---SHORELINE DURING 1972 LEVEL OF DEVELOPMENT ---PHYSICAL CHANGES PROJECTED THROUGH 1985
-------SUBMERGED SPOIL DISPOSAL AREASTable 1. Physical changes made in Tampa Bay since 1880 Index no. Approximate Index no. Approximate (see figs. Description surface area (see figs. Description surface area 3 and 4) (sauare miles) 3 and 4) (sauare miles) I



### ------ Causeway



## ------------------- 0.04 36



### ------ Causeway



## ------------------- .09 2



### ------ Causeway and residential

______ .07 37



### ------ Commercial

__________________ .15 3



### ------ Causeway and commercial

_____ 

### .13 38



### ------ Causeway



## ------------------- .54 .:1 "nrl 

## . , 1.1 10 .,1\



### ---- 

# '.

---- 

## ------------ 5



### ------ Causeway



## ------------------- .22 40


### ------ Commercial

__________________ .27
o

______ '-.-ommercial ano spoil oisposal

_ .I:l 41
______ KeslOenual

___________________ .12 '7 

# - 

# .. 1 

### A" ., ',' 

## .""

- ---- -- - -- ---- - -- ---- ---- 

# .. 8



### ------ Residential

___________________ .59 43



### ------ Residential

___________________ .10 9



### ------ Commercial

__________________ .76 44



### ------ Commercial

__________________ .08 lU

______**~POlJ** Olsposal

________________ .11 4'

______ commerCial

__________________ .23 II


### - Spoil disposal


### -- 

### --- .06 46


### ---- Commercial


### --- - .03 12



### ------ Spoil disposal and bird sanctuary .02 47



### ------ Residential

___________________ .09 u

______ :SPOil disposal and bird sanctuary .04 48

______ Causeway



## ------------------- .13 14

------ Spoil disposal

________________ .05 49



### ------ Residential

___________________ .43 15 Commercial

__ .05 "i0 .:10


### --- - - 

### - 16



### ------ Commercial and spoil disposal

_ .23 51



### ------ Causeway and residential

______ .40 17



### ------ Commercial and causeway

_____ .86 52



### ------ Residential

___________________ .39 III :md l"ifl 'i1 1,<; 19



### ------ Commercial

__________________ .23 54



### ------ Causeway and residential

______ .29 20

------ Residential and commercial

____ .30 55



### ------ Residential

___________________ .21 '1 

# - 1 IS/ '\,<; D I\A


# ------ -------- --- 

### -- - 22



### ------ Military



## --------------------- .12 57



### ------ Causeway and residential

______ .79 23



### ------ Spoil disposal

________________ .24 58



### ------ Causeway



## ------------------- .19 "::4

______**~POII** disposal

________________ .Uj**,~** ______ Causeway



## ------------------- .19 25



### ------ Commercial

_________________ .08 60



### ------ Submerged spoil disposal

______ 8.59 26



### ------ Commercial

__________________ .23 61



### ------ Ship-channel construction


### ----- 4.69 2/

______ Causeway and military

________ .11 62

______ Spoil disposal and beach 28

------ Residential

___________________ .18 nourishment



## --------------- .16 29


### --- Residential

___ 

## ------------ .25 63


### ---- Snoil disDosal S/I 30



### ------ Commercial and residential

____ .03 64


# ------ Spoil disposal

________________ .02 65



### ------ Spoil disposal

________________ .02 31



### ------ Causeway



## ------------------- .13 32



### - Commprri:ll Ofl F.,<; "'n,,;l 011 33



### ------ Causeway



## ------------------- .02 67



### ------ Circulation-inducing cuts

______ .47 34

------ Causeway and beach

__________ .19 68



### ------ Submerged spoil disposal

______ 3.12**~~** wiul:'uiJJg J"J 

### ---- - ---- ---- .1 U:7

_ ___**~U1P-** 

### - - 

## .,'+
ferences in the boundary definition oflower Tampa Bay. part ofthe dredged material became new emergent upland**~.** 

# . . . . 

# .. 1111; r 111**I:'a~ll** to' oJ <oU,", ·C ...... U". 6<OU' .u " <oL'" v.**~lll;** U<oy. from 1880 to 1972, from 1972 to 1985, and from 1880 Under these conditions, the average depth also increased to 1985 also are given. The largest percentage changes because larger water volumes are divided by smaller surin surface area, volume, and depth were for Hillsborough face areas. Bay. Between 1972 and 1985, only Hillsborough Bay and Dredging and filling from 1880 to 1985 will have relower Tampa Bay subareas sustained any changes in the duced the surface area of the entire Tampa Bay system


# . 

# - , , 'non#' 

## .

# ..

.. OJ**~lla~** all:' l;;lVI;U 111**~aUll;** ,(.. uy.:l.u

. uy l.7U-', "<0."1 "U1 U<OV" ;n .,,."'., I.",,,, • .,hl", ", r",f'I",
.... :n 1:1",,, h" 1 't .,,,,rl .h", ...16_+1.
... :11 -, -r -" -" 0 

### , -Q. -r tion of islands, causeways, and other fills. Increases in have increased by 4.4 percent. water volume occurred because (1) the source ofmaterial Changes to the physical characteristics ofTampa Bay for most fill construction was the bay bottom and (2) only influence the quantity ofwater that enters and leaves each Introduction 7Table 2. Physical characteristics of major subareas of Tampa Bay and of Tampa Bay overall for 1880, 1972, and projeClea I**~o,** levels or aevelopmem 'co. &: &. • & 

# ... "_1,.-

. &, - •• ,_• ._".&_, •• 1.:
...... ____ I
...... 

### - • ,**V~r.;~~' n~.,,~**  nf 10"01 '0 -, "T Percentage change nl 

### ., ,nn"**.n~~** 1CC"**ch~;a~teristic** Area 1880 1972 1985 to to to 1972 1985 1985 Approximate

__ Lower Tampa Bay

__________ 128.4 126.1 125.9 

### - 1.8 -0.2 

### - 1.9**~lIrf"r** .. Mitltll
..**T"m~** R"v III , 1M 'Ii 100 'Ii 1 'Ii 0 1.5 area, Old Tampa Bay

____________ 77.8 74.8 74.8
- 3.8 0
- 3.8 in mF. Hillsborough Bay

__________ 42.7 38.8 36.9
- 9.1 -4.9 -13.6



# - .- 

# - . , 1 i1l1lpi1 Di1Y \LULilIJ 

# --- ;lOUd**;l'+"7.~** ;l'+ .1 ;l.U .V J.V Water

_______ Lower Tampa Bay

__________ 1,572 1,578 1,578 + .4 0 + .4 volume, Middle Tampa Bay

_________ 1,475 1,481 1,481 + .4 0 + .4

_ a &. AI..! 'T"n

__n Dn**~ll{) ~()C**  CClC () () a


# - 

# .. " 

## - 

# -- Hillsborough Bay

___________ 352 373 388 + 6.0 +4.0 + 10.2 Tampa Bay (total)

_____ 4,088 4,127 4,142 + 1.0 + .4 + 1.3 Lower Tamna Bav

__ 12.2 12.5 12.5 + 2.4 0 + 2.4 depth, Middle Tampa Bay

_________ 13.3 13.5 13.5 + 1.5 0 + 1.5 in ft. Old Tampa Bay

____________ 8.9 9.3 9.3 + 4.5 0 + 4.5
n n, ,n r 

# .- n • "'0 n U<L]

______ 

# --- 0 .... 7.V JV." . J • J ,.**~u.v** Tampa Bay (overall)

___ 11.4 B.8 11.9 + 3.5 + .8 + 4.4 Approximate

__ Lower Tampa Bay

__________ 248 246 246 - .8 0 

### - .8 t;A..l 1\.,f;AAI
.. T"",n" ll" ')1'7 ')1< ')'t< II 0 II 

# '. prism,1 Old Tampa Bay

____________ 190 187 187 - 1.6 0 - 1.6 in mF-ft. Hillsborough Bay

___________ 99 95 93
- 4.0 -2.1
- 6.1 Tampa Hay (total)

_____ 774 7fi5 70T T:Zr .j 1.1 IThe volume of water that enters or leaves a tidal water body between high slack water and low slack water.



# ... '- '-'.' 

### ., .....L· ." -' 

# .. ,. -'- 

# ..,,,-, 

### '.L'_ .L

• •.•**~~_6** 1""6 }J<LJ • V J ...... Vel)' " 

# ........... ]

# .............. ................ VJ ...... .......... OV--.uIIIIO 

# .

# - ,. the tidal prism and is defined as the volume ofwater that tween the limits of high tide and low tide altitudes). enters or leaves a tidal water body between high slack The following sketch shows an extreme example ofthe water and low slack water. Tidal prism is approximately impact that reduced surface area can have on tidal prism equal to the surface area Umes a representative tidal range for hypoilletlillprismatic estuaries havmg the same total ofthe water body. Even though thetotal volume ofwater water volume at high tide. n, ..! , •• - 

### -_..:I

- - n¥6_ 'l Ar "r.." 

### Ar

......... p ....... ]."**-~ ~,**  

# ..... (;1I;n .. th
.. t;I'1,,1 nr;orn**;~** -' (OP.. t,,},I
.. ,\ T},;o An. TotAl volume ABC Total volume ABC

. .., parent anomaly is explained by the reduced surface area Tidal prism 

### == 2aAC Tidal prism 

### == aAC I 

### I I A I

. " I 

# /T / -r- /C// 

# /// A 

# // ///

# ~I**~//** 

# /1**~~//** 8=2A 

# v-:/ / Ign tlce / 

### a Lowtide--

- 1------ 

### V 

# f----r--- 

# / / 

# / / 

# ,/

8 Tidal·Flow, Circulation, and Flushins Chantes in Tampa Bay, Florida

### The tidal rism and associated ercenta e chan es for Tampa Bay and for each major bay subarea are given 10 

### ta e .

Tidal prism reductions from 1880 to 1985 are expected

o e wri en commun., une developed and applied a two-dimensional, hydrodynamic Hillsborough Bay. In two master's theses prepared at the University of Sout Flonda, R. D. Ghioto (written commun., March two-dimensional, constituent-transport model having 40 segments or cells. Little information was developed during this study regarding tidal circulation and flushing in

gyres or net rotational features existed in the bay that apacteristics. Results from a similar model reported by Ross (1973) showed a different gyre pattern than that computed by Cote. Such differences confirm that circulation ists. Modeli results from this stud show, however that

either directly or indirectly concerned with tidal effects in Tam Ba. As back round and reference information, many ofthese studies are briefly described and discussed herein. Studies oftidal motion in Tampa Bay were first underi c ns ruc ion, vera i exc a ge throughout the bay is marginally reduced, and, conse- 

# .. . for lower Tampa Bay, 0.8 percent for middle Tampa Bay, 1.6 percent for Old Tampa Bay, and 6.1 percent for Hillsborough Bay. These changes indicate that, as a result of
dredge and fill also cause circulation increases that more than overcome the effects ofreduced flushing potential

U.S. Coast and Geodetic Survey, as part of its mission to chart the coastline ofthe United States. Because water depths are measured from a constantly changing water surface, referencing water-surface altitudes to a meaningful navigational datum, normally mean lower low water one or more of the following items: 1. choice of hydrodynamic model, 2. sc ematlZatIon 0 

### ttom con IguratlOn, 3. grid size, is defined as the average of the lowest low-water height of each tidal day observed over a tidal epoch of 18.6 years. Shorterperiods ofobservations must be corrected by comparison with simultaneous observations at a longterm control station. Tidal stage data were first collected 1947.

By analyzing tide data in terms ofharmonic constituents, the NOS has predicted tides (U.S. Department of Commerce, 1982a) each year since 1939. Tidal currents



## . . designed to extend tidal current predictions to unmeasured locations also have been published (U.S.

epartment 0 

### Commerce, 1951). e most recent NOS survey, 1963, of tidal currents in Tampa Bay was described and summarized by Dinardi (1978). His report grammetrically tracked drogues and foam patches. Data from Dinardi (1978) were used to confirm tide-induced, resl ua ve oCltIes compute urmg t IS stu y. 5. choice of tidal boundary function. It 

### is important to note that there are no fixed patterns point out that circulation is an ever-changing quantity that evolv s in res onse to chan in tide wind and oth r driving forces. Determination of a truly representative or average circulation pattern must be deferred until exhaustive measurements and computations are under-



## . . . conditions will differ because ofcomputational sensitivity to the above items.

tion Control Administration to determine the source of features.

Introduction 9

### Computer studies oftidal mixing in upper Old Tampa Bay were conducted at the University of South Florida Earth Resources Observation Systems Data Center is also appreciated. by Ross and Anderson (1972). A two-dimensiOnal, hydrodynamic model having a grid size of 14 

### mile was de- T1.

__**.~..l_1 .1.~.'**  ..... ..**~"** 

### DESCRIPTION OF COMPUTER SIMULATION



# _



# ..

# _--

simulated InfOrmatIOn IS desued. These equatiOns are

cal procedures, Input requuements, ana operatIOnal ing location in the real system. The following sections describe the equations, numeriphysical laws governing water and constituent motion in two dimensions are applied between every location where



# . - or 

### tne SYSlem.


### Water motion in estuaries is governed by the physical laws of conservation ofmomentum and conservation of mass. The two-dimensional estuarine simulation system

The model used in this study can simulate water and constituent motion in well-mixed estuaries, embayments, "nrl nth
.... "n"ct,,! 0 .... ""
- th::lt • thE>



### r:, sOlveo at small ume :SLCV:S LV r i:l I,;Jv:SC 

### approximation of the time history of water level, water ::Inn
. 

### at each ndHigh and low uniform constItuent concentratIOns were initially assigned to the water on the landward and**~;..l~ ~".1.~**  •**T1.~ ~ft~~** **~"** -r 

### the bay. An effective method was used to determine changes in flushing characteristics caused by various alteration options to the Courtney Campbell Causeway.

as a basis for flushing comparison between alternatives. Goodwin (1977) compared computed residual tidal curtsay. t'rellmmary CUCUlauon results rrom a aetauea moael of Hillsborough Bay (Goodwin, 1980) showed complex net tidal currents that had not been previously detected. Comoarisons were made between comouted flow and cirbut that little potential existed for improving overall circulation between waters ofHillsborough Bay and Tampa , -r 

### nt**trlln~ferred durin~**  

### one tidal cycle was used
rents In HIllsborough Hay tor ISlan<1S ot vanous configurations constructed from materials dredged from the**~h;n** • U.. •• th"t'

-r • 

### could be modified bv**chan~es** 

### in island**confi~urations**



### culation patterns for conditions both before and after the Federal dredging project begun in 1976. (SIMSYS2D) applied in this study uses vertically integrated forms ofequations that describe conservation of UIOvannelll**(1~!S1)** 

### usea the results ot Uoo<1WIn**(l~!SU)** 

## . ._. a" UIV'''' LV a "au- -r UIV"'''I LV -r "VU

### ductance changes in Hillsborough Bay off the mouth of the AlafiaRiver. He found that a 17-fold increase in river discharge (40-680 ft3

### Is) produced a 25-percent reduction in the specific conductance (40,000-30,000 ILmho/cm) 

### of bay water near the river mouth. Specific conductance at


# .. .. .. . .._n mass anl:fmOmenTum, as given-o-yLeenoense ana urinun**,.~....** n' \"7 ", 

### v. UJ. (1) 

# at ax oy au au au 

# ar U(U2

### + V2)O.5 

### -:::-+ U --;:-

### + 

# v--;:-- f V

### + g -:::-

### + g ro, r..T U1C llYCI JJ1UUUI wa" uy JJ1V1C Luau 'U r 

### This reduction in specific conductance indicates significant mixin2 of river water with HilIsboroue:h Bay water 1



### -- 7/=0 (2) near the Alafia River. Acknowled2ments 

### We are grateful to the Tampa Port Authority, particularly Delmar Drawdy for initiation and coooerative financing of this study from 1971 to 1973. We are also U u.... UJ' UJ**~~.** I



### -- 7/=0 (3)



## en grateful to the U.S. Army Corps ofEngineers, Jacksonville District, for continuation ofthe study and financial • , ... n :SUVVUlL _""**1:70~.** 

### Large computer simulation runs that culminated this study were made possible by the Defense Communications Agency (DCA) Hybrid Simulation Facility at Reston, Va. Without assistance from DCA, a full-scale study could not have been made.

T .• '.' ••• • 1. T T .1: .1._ D

__ ..l 

### Survey research staff on a precursor of the models described in this report is gratefully acknowledged. Enhancement of satellite imagery by Gerald Moore of the where f=the Coriolis parameter, 

### 2w sin¢ (S-I), where 

### -• . ".L"'" W 'LUC VI "I" ...,.... L" 

### its axis (radians per second) and cP 

### = geographical latitude (degrees); g = acceleration of gravity, in foot per second squared; 

## e= water density, in pound·second2 

### per foot4 ; 

# . .. 

# . 

# - waLCI-IC 'Cl flUI -r**.~** ...**nlftn~ ;~**  " ....t.

r 

### H = 

### h (distance from the reference plane to the embayment bottom, in feet) 

### + 

# r= water depth, in feet; 10 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

### C=Chezy roughness coefficient, in footo. 5 

### per where st:conu, V. 

### ;OlsperslOn COet1Iclent, How In the x 

### OlreCtlOn, 

# . . ,

# . . 

# .**.~** 

# .......**~~** 

# ..**_~~** . III U";;A 

### ,**III"~~,** 

### in pound per square foot; Dy

### = dispersion coefficient, flow in the y 

### direction, 7/= surface wind-stress component in the V

### direction, in sauare feet ner second' and in pound per square foot; and SA 

### = source and sink function, including the rate t 

### = time, in seconds. of injection of constituent A. The variables U 

### and V 

### are the vertically averaged As with the velocities U 

### and V, P 

### is the vertically inte-



# . . . " 

# .. Vi llVW**as~** 51 < .. "u _0 111<1"" vi ,",," 

### 1 

## t u dz 

### given by U=- 

### (4) 't rr 

### .**,~ ~~**  ·h**P=~** 

### PA U.. F"J 

### V=_1**I~** 1'1 

### -h v dz 

### (5) H 

### -h where PA 

### is the local mass concentration of a particular where u 

### and v 

### are the point-flow velocities in the positive constituent substance, A. Holley (1969, p. 628) noted that, except in regions of x 

### andy 

### directions, respectively. and dz 

### is the differential 

# . in the vertical direction. The wind-stress components are ICll !>" , Ill""" -, 

# .. 1..
..**:~ ~~+~_**  •• ••**~_** .11 

### given by Dronkers (1964, p. 188) as: 'J 'J 

### with mass transport by advection. Leendertse (1970, p. 7: = (Jea w2 

### sin if; (6) 13) reasoned that, ifthis were true, small errors in assignana 7:= (}eaw2 

### cos if; (7) ing values to the longitudinal dispersion coefficient would where not substantially change the solutions obtained. He then () = wind-stress coefficient=0.0026, from assumed that dispersion could be adequately defined by T 

# . .... 

# - . " (\"" (\\ 

### hlln <>., • 

### .thp 

# .... \'J ", P_ JI' -r -'" 

### nondimensional, effect oflateral mixing and a directional component apea=air density, in pound·second2 

### oer foot4 , 

### proximating longitudinal effects. The dispersion coeffiw 

### = wind velocity, in foot per second, and cients, D. 

### and Dy, 

### used in SIMSYS2D are given by 11'
- 

### angle between wind vector and y 

### axis, in Leenoertse {1':l7U, 

### p. 14 

### ana**~4)** 

### as: degrees. D. 

### = dHUgo.sc- 1 

### +Dw 

### (10) ..,

.

### " " 

## . 

# . VIllI""" 111 ... V ,_. 

### sions. Equations 2 and 3 express continuity of momen- Dy=dHVgo.SC- 1 

### +Dw 

### (11) tum in thex 

### andy 

### Cartesian coordinate directions, respec- where tively. These equations assume that water density is con- Dw 

### = a diffusion coefficient reoresenting wave, stant both hOrIzontally and vertically, that vertical flow wind, and lateral mixing effects, in square components do not exist, and that horizontal flow com- feet per second, and ..l**~~+** 

## .... 

## .. 'T'L ..... 1· 

# . - 'J ....**"'V~~1 .~**  111 U 'an SUlllliU tV 

# .- tn J:lrpJ:l<: tnJ:lt J:lr
.. •• <>.,r1" "

# .. 

# . ..... " "**,...~,...\** -oJ 111<11**--uy~~.** 

### well mixed. However, this type ofmodel has been successfully applied where gradually varying horizontal density 

### Numerical Procedures graolents occur_

Transport of dissolved constituents is governed by Partial differential equations 1, 2, 3, and 8 describe 1 .1**'~.' ~~**  ... +

__ .. _ .... 

### general relations that exist among the manv forces that

-e> 'J 

### control water and solute motion. Because the equations bv fine-scale disner<:ivf" or 

### l'll'tinn l'l'll1<:
..ti hv 

### presence ofturbulence superimposed on the average flow_ cannot be solved analytically for most real-world condiTransport of dissolved constituents is governed by the tions, procedures have been devised that provide approxi-



# . .. . 

## .. conservatIon ot SOlute mass. Transport Incorporates 111<"" vy U"lll!> IV 

### -" 'OJ**P~IIVl"l** .... 

### advective and dispersive concepts and allows for consti- enormous quantity of numerical computations. tuent sources and sinks as given by Leendertse and The numerical procedure used in SIMSYS2D is sumGritton (l971 n. 

### 4) for two- _. flow 

### marized below and is presented in detail by Leendertse 8): and Gritton (1971, p. 15). Equations 1,2,3, and 8 can a(HP) ..j, 

### (HUP) a(HVP) 

### be approximated over a region in time and space by a 1____ • .." •• -- • 

### n_.'·-**~~** 

### at ax ay '0- I 

### ill dmilJ:lr in 

### fnrm tn th
.. 

### nJ:lr
..nt •• _- f"11 II

### l'l- _a{HD.

# ~~**a{HDy~~** tion but is applicable at only one point in time and space HSA-O 

### (8) and is separated from all other points by finite time and ax ay 

### space increments. Such a finite-difference approximation Description of Computer Simulation System 11

### is valuable because, by using the approximation, a differCIllliU IS 

### to**,u~e** 1. • • • • •

....... "'.0 cu.



### Each difference equation contains known and unknown terms. As long as the number ofequations equals the number of unknown terms, the system is solvable. The method of solution for the unknown terms involves a point-to-point, repeating, stepwise procedure that in-
• .•. ...I. 

### tional elements defined at integer points and midway be-

• • -. .., 1:_ 

### Leendertse and Gritton (l971, p. 11) give a complete description ofhow equations 1, 2, 3 and 8 are structured at each (x, 

### y, t) 

### point and how unknowns in each equation are solved. An overview of the solution scheme is given also by Cheng and Casulli (1982, p. 1655). 

### Input Requirements -r 'J 

## ... appropriate.

A**space-sta~gered** 

### grid scheme (fig. 5) is used in the I 

### nree categones or input aata cue SIMSYS2D model. Water levels 

## (n and solute mass denSlty (p) 

### are dehned at mteger values or 

### mana n. I 

### ne reference water depths (h), 

### measured from the NGVD of 1n"n**~.~ .~.**  • ..**~~:~** .. o intpapr**U~l11P"** 

### SIMSYS2D: 1 ••• nf
. 

## . LU :mci initi::ll


# ..**'-~''''** 

# - ofboth 

### m and 

### n. Velocities in the y direction (V) 

### are defined at points midway between integer values of nand at integer values of 

### m. Velocities in the 

### x direction (ll) 

### are defined at pomts rniC1way between mteger valUes or 

### m and at integer values of 

### n.**'T""'~ ~.:...I**  .. ..hA •**~f"** ..hA ::Irp,. 

### conditions, 2. definition and characteristics of the fixed boundary (bay bottom and land surface), and j. 

### aenmuon or me anvmg runcuons UI 

### due, winu, tributary inflow, and constitutent sources. Thp r;rd • thp W::ITt>r cii"nt>r-
• .. ·0' 

### in the positive and negative 

### x and y 

### directions. On land areas, reference water depths (h) 

### are replaced by land altitudes (- h), 

### and water velocities are computed only at tImes when water levels exceea lanu anlIuaes. ume (t) 

### also is simulated in a stepwise manner, with computason coefficients (see equations 10 and 11), starting constituent concentration distributions, and starting watersurface altitudes. The lateral dispersion coefficient (D",) 

### ana starting concemrauons can oe spedlieu il:> 

### unique values at each cell in the model.



### ::**~.**

# .(~:.: 

### .... 

# +-+-+-+-+-+ 

# I +-+-+-+-+ + I 

# +-+-+-+-+-+\'+ n+3 

# + - + - + - + - + - + 

# I +1 

# I I f"\ 

## I f"\ 

## I f"\ 

## I f"\ 

## I f"\ 

## I 

# + + 

# + EXPLANATION Water level and solute concentration location

m-2 m-1 m m+1 m+2 m+3 n I T 1 

## 0 T1 T 1 T 1 T 1 T 1 

# I + I t time-step index 

# o 0 0 0 + I t+2 m x direction grid index Velocity y direction location -VefocitVx OlreCllon lOCation 

# I 

# o Water depth or land altitude**I~_~":~-**

hwing 1m, n) IUblcripts II EncloHs.1I grid eIementa 

# n+-+-+-+-+-+ 

# It +1+ 

# 1 I ...... I ...... 1 1"'\ 

### I 1"'\ 

### I 1"'\ 

### I ITT I I I T 

# I + 

# I n+2 

# + - + - + - + - + - + 

# I

I I I
...... , ...... I
...... I 

## + 

# I 

# n+1+_+_+_+_+_+ 

# I + 

# I 

# 10101010101+11+

n - 2 

# + - + - + - + - + - + 

# I t ' " y direction grid index 

# I 0 

# I 0 

# I 0 

# I 0 

# I 0 

# I + t-1
n**.~** ...L. ...1.. ...L. ...L. ...L. ...L. .. ., y : : '. '. :" " :

:
: ::
" " ': : : :
::: ::: / '



### .................................................................................................................................................................•......•..................... 

### , x 

# - Figure 5. Finite-difference scheme for computer SimulatIon mOdel \modltled tram Leendertse ana uTluon, I**~/** I}. 12 Tidal·Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

### The second category includes information on the tion at all locations in the model at sufficiently small time physical size and dimensions ofthe estuarine basin. Basin increments, usually 30 minutes, to define the time variageometry IS aetmea by specltymg a water aepth or lana tIon ot computea vanables. Computations 

### aone between altitude at each model cell. The resistance to water flow- the time intervals of SIMHST are lost. SIMHST is the 0"'''**""o~** fho**;~ ~.**  J..., ..ftl**,~o I'~~** **~"** ..**~,..o** ,,+, ... 11**.~oA** ._**.l..~** DAC''T'

.c> 'J -r -c> c 

### Manning's roughness coefficient (n) 

### at each cell. PROCESSOR section. The third category includes information that can be In the initial step (POSTGEN) of the POST PROentered as functions of time. Tidal fluctuations are de- CESSOR section, the SIMHST tape is read, and several tmea at the ocean bounaary. :Speea ana auectIon ot the speclauzea alsk aata mes, each usmg Only a small part wind is defined at the water surface. The rates of water ofthe total data available, are created. Each disk file is .,,.,rl ,,+, 

## .**"~o** •**~.** ...f
. I",..... fl.
..,., .. ..rl**.,~** ;,., ......f f"**.~** 'rr r -r • ' r. 

### lnnp] tions to simulate rivers sewae:e outfalls dye injections to nroduce mans and e:ranhical disnlavs of m, 

### I**rp~l1lt~** 

### and so forth. (fig. 6). The post-processor programs are frequently changed as new ways ofviewing or applying the data are concelvea.**~eparale** 

### programs or me**ru~** 

### I \.1n1'1 

### type are 

### Operations often needed to create special data files from SIMHST fnr
..

### .,,..h ,.,..,,, 

### ,. SIMSYS2D is comnosed of several interrelated nrograms and files, as shown in figure 6. The system has four main sections that have distinctly different functions. 

### MODE L DEVE LOPME NT AND APPLICATION Ine INru 1 IA A 

### r '''' {iVY} 

### scans the user-prepared input data file, often several thousand card Model development is a process by which a general images in size, and checks for many potential format and estuarine simulation system is structured and adjusted to**lo~ic** 

### errors. This step detects as many errors as nossible represent a particular estuary. embayment or other before submitting the data to the more lengthy MIXER coastal area. The objective of the process is to achieve and simulation-computation'steps. Data listings and error as close agreement as possible and practicable between messages are prmtea to gUlae error correction. Slmulatea ana ooservea valUes ot tlaal stage, Haal curnr,·.L • .S: Tn..... "",_, s:" • .,... ... LL •

'H" V.**~~~** , u .. "''''
....**.,~** ... "'.,**~.'"** 

# ."''''''' , ....... v ... "'• ,

# ..."'- written for subsequent use. (1) 

### The SIMULATION IN- tors. The closer the agreement, the more confident model PUT (SIMINP) file is a restructured version of the users can be that results of subseauent numerical exoriginal input data that matches requirements ofthe com- periments accurately reflect real conditions. putation section ofthe system (SIM2D). (2) The SIMPTl The development procedure is composed oftwo basic file contains input overrides that allow minor changes to steps, calibration and verification (fig. 7). Both steps in- -' '

# .. -, ,J: .I 

# _ . v", ........'" .v u.'" "'puc ........ , puv••v 

### , • v'**,~** v • ....u**vv,,~. y~U**  Ui:lLi:l. 1 He 

### having to rerun the IDP and MIXER sections. The most calibration step has a feedback loop that is not present common input override chanlZ:e is settinlZ: ofstart, restart, in the verification step. Feedback allows adjustments to and end times for simulation runs. (3) In the SIMCOM imprecisely known input data to improve the match befile, the size ofall dimensioned variables for each model tween observed and simulated data. Verification is conapplication, as determined by IDP, is stored as common ducted for one or more data sets that were not used dur- s:. .L ••**.~.** J:, • v.**"'p~** .v ... '" ..**"'~.** ,- -,

# . "'eo .c> 

### ,**.~** 

# ...."'. 

### The MIXER section combines SIMCOM with the are not allowed. The degree of agreement achieved beFORTRAN source code ofthe model. Compilation and tween observed and simulated data during the verificalinkage-editing steps produce an executable load module tion step is a measure of model accuracy and reliability. that IS tailored to each geographic area bemg moaelea. The tollowmg sections aescribe how bottom configuraThe computation section (SIM2D) executes the load tion, boundary conditions, and initial conditions were

• • .l..ft'
... ft. 

# . • J.. ...**IT'~~** ft_A • • • ft_A**~h" ~o~'** **.1+~** ,,+, • • _...I**.~.** 

# .. 'J 

# .- 

# - SIMINP and SIMPTl data files created by IDP. Com- tion comparisons for development of the Tampa Bay puted water elevations, transports, constituent concen- model. trations, and other variables are stored at user-selected tIme mtervals on two tape meso Ine restart tape (SIMRST) contains sufficient information to restart 

### Bottom Configuration

...f • 

# .. , ....**n;,.,f~ ~n**  fh.,f**,..n~fhr** 

# - 

# .. tions do not have to be reneated in case of nroe:ram or The area ofTamna Bav and the Gulfof• I 

### ,**chn~pn** 

### computer failures. The restart capability canbe used also for application of SIMSYS2D is shown in figure 1. The to segment long simulations into small, manageable total modeled area was 826 mF, approximately 45 perlengthS. The history tape r... 

### II} contams mtorma- cent ot WhiCh was lana tnat naa altItuaes hIgher than Model Development and Application 13;;::::::::::::::::

### . : INPUT;'

..**:::::::::;:::::::~**

•••••••••••••••• u 

### .:;:·'oATA··;W .:::::::::::::::::::



## ...............................

.i:

### ····PROCES·SOR··..

# :r**~::::::::::::::::::::::::::::;:::** Printed

.....--I-:.,Iif, 0 utnut lOP data Process input**/SIMCOM~** / SIMINP "" /SIMPT ,""**.~** Common 

## ):k Simulation**)~ Ov~~:~~.~~**  to ) ( Input \ 

### ..i: .\. data r'W':



# ------- .- .- EXPLANATION

/ Model","", 

# :::t- M_ix_e_r

__---l ( source .. Combine comoile :::: Computer program or

, : command list

.:::::::::::::::::::: 

### I ,;; MIXER r .::::::::::::::::::::: Printed (' Load

# ~." 

# :,,/ 

# ,**~kstorage~ :;~::mm::**  ...

### :,·~

Printed output .1" . 

### .i!:**(.~~.~I?~!~!!~.~L** 

### . output 

### _ . 

# I SIM 20 ...;; l.Umpuul.,."gll, velocity. concen-

,.... tretion,

### a~~.~~**~:.........** :: ! :;.::::::: ::::::::::::,::::::::::::::::::::' :.::m::m;;m;;::''''

# ~~ I Restart )- 

### 1 Historv 

### 1**------------------~-------------------**
i

# l files stage,

### ~::: Generate post- : velocity, transport. processor files \:. concentration. and so on .,' ::: .: ::: . 1 .::...**~.~:;>** .....;:

### .;!:::~~~~~:~:=:/ Plot programs

for graphs and maps .:.':::::::::::::::::::::::::::::::::::::. Plotted output ::;::;:::::::;;::::

### ... FilllJ rp (, rof filec inn, ,t ...**"rl~, ,t~,**  ,t**f~.** thn '0

14 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

## .' 

## .'**,:~.** DETERMINE REGION ;:: AlUn**~Dln** C>'7C .':. OF MODEL

# ~~;!!!mm!!!!mm!!!t!!m!!m!m!!!!::' DETERMINE WATER PROPERTIES AND BASIN BATHYMETRY

.', 

### .... :.:-:.' ,,"VLL<o" 

### LI,. I,. (stage, inflow, wind)

# }~!!m:mm!!::mmm!!~mm:mmmmmm:' :,.**,,"VLL<O"'~** '<O"'VY' UI"\ 11"\**:~::** (stage, velocity) :;:1m!:mm:m!m!:m!m.!!!m,mmm::!m!!:· 

## • • ,'" PREPARE DATA FOR \: INPUT TO MODEL .'**~.~** :.: PREPARE DATA FOR COMPARISON WITH COMPUTATIONS 

### - I OPERATE SIMULATION**~Y~T~U** /f;n iiI**.:;1(,:::::~~EI:~~~¥K)~:::::::::1!lil!:· .:::::::::::::::::::~t::::::::::::::::::::::::::·**  

# , ·:.:1 I**:~;!m:mmmm::m::m,mmmm::m:mm:'** 

# ---------r-----------' :,f**,~,** 1**",v~"** ..**",v~"** v ,**~~** AND OBSERVED DATA


## •
·.·or 

### ." 

### ::s: nev,;:,e IVIUUCL INPUT AS APPROPRIATE**~",,,,<or ~"Le**  DEGREE OF CALIBRATION?

I BOUNDARY DATA _

### .-:!~mmm::mmm::~:~:~**_:.~;~!~:;!~~!~m:.** _ 

# , ,**.,:~** rn, crT**'::~** PREPARE DATA**~()R** :.;, INPUT TO MODEL

## ~;;m::::!!!m!:!!!!!m!!i!mmmm!!!!!!!:· :0• •::- ..**~.** .. UAIA I'UH

• •• i:·:!,.:':; COMPARISON WITH COMPUTATIONS 

# <: OPERATE SIMULATION :.:.; SYSTEM (fig.G) 

# , .-:::::::::::::::::::::::::::::::::::::::::::::::::::::::::' 

# ,

'::; COMPARE COMPUTED ••.• ANU UAIA :':. TO DETERMINE .::.: DEGREE OF :;::' VERIFICATION

### ~:~~::::::::::::::::::::::::::::::::::::::::::. Figure 7. Calibration and verification steps in model development.

Model Development and Application 15

### 12 The bay bottom is treated as an impermeable, immovable boundary that causes resistance to free flow of boundary in the GulfofMexico, and the water surface.

the model. A related open-channel flow equation by A description of the data used to describe conditions at

material increases. Values of the roughness coefficient, 

### n in Manning's equation, were assigned to each cell of eac oun ary 0 

### ows.

to convert from Manning's 

### n to Chezy's Cis: ezy mcorpora es ano er 0 

### om-roug ess coe 1- 

### cient, C, that is actually used in model computations (see

either 1: 10 000 or 1:20 000. The densit of covera e Manmng's 

### n IS an empmca coe lClent t at cannot e measured directly. By varying the coefficient, modelcomputed tidal stage and current can be adjusted to closewhere 

### H is the water depth, in feet. e 0 

### Resurveys of selected areas were made by the U.S. Geological Survey in 1971 and 1973 by using automatic

ositionin e ui ment and a di 'tal fathometer. The objectives were (1) to determine whether any significant, areally extensive bottom changes had occurred since the ranged from about 100 to 1,000 depth observations per square mile. For this study, all depths were adjusted to

surveys. Direct stereo-compilation ofbottom configuration also was conducted wherever low-level aerial photography could sufficiently penetrate the water column to define bottom relief. A description offathometric and photogrammetric approaches is given by Rosenshein model computations. In a study of Jamaica Bay, N.Y., L n ertse 1972 . 11 used 

### n .alues that ran ed from 0.026 to 0.034. For areas ofcorresponding depths in the St. Lawrence River, Prandle and Crookshank (1974, p. 523) used a Manning's 

### n of0.028. April and others (1975, changes were detected. Depth assignments were made by using a combination of automated and manual techniques. The automated proce ure ( a rane an a tzer, mvo ve compilation, editing, combining, and gridding of data from



## . 

# . observations were fitted to a polynomial surface from which a representative depth for each cell was computed. The cell depths were then compared with bathymetric charts an manua yrevise 1 

### necessary. evlSlons were sometimes needed near shorelines and channels and in for Mobile Bay, Ala. In a study ofMasonborough Inlet, N.C. Mas h and Brandes 1975 . 230 used 

### n values that ranged from 0.018 to 0.035 for depths from 4 to 30 ft. Beauchamp and Spaulding (1978, p. 525) used an 

### n value of 0.028 for the Long Island Sound, Block Island


### , 

## , New England. Wang (1978, p. 505) used an 

### n value of 2 r th Bisca e Ba Fla. An initial 

### n value of 0.025 was chosen for this study on the basis ofthe most comparable conditions reported in the literature. Other 

### n values, as low as 0.022, were Land altitudes for cells that were higher than mean high water were assigned a default value of 3.0 ft. This value limited the model to investigation of tides that reached maximum a 1 

### u es 0 

### ess an. IS Iml a Ion was not a constraint for this study. of0.0235 was chosen as providing the best fit to prototype data. Whenever water depth in any cell became less than 1 ft, however, the model automatically reassigned an 

### n value of 0.040 to simulate the increased importance of bottom friction.

Boundaries of the Tampa Bay model include the bay bottom, the shorelines, tributary streams, a seaward The shoreline is defined as a no-flow boundary except where tributary streams enter the bay. A flooding and 16 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

### drying feature of the model simulates landward or seaward movement orthe shorelme with changes 10 

### tlClal



## . 

# . . . . Stage. 1 

### IllS IS Jess III 1 i:Ullpi:l Di:lY wm::ll 

### compared with other coastal plain estuaries that have ex-**~rp~c:** nf**titi~l** flM.C: 

### Freshwater inflow ofstreams tributary to Tampa Bay (fig. 1) was determined from data published by the U.S. Geological Survey (1977). The freshwater inflow used in _'-I f. •• ,",' • ••. • ...

..." ULV"'''I \.avI" 

### oJ, I" "I" al
..lU<11**.~** U .. IV'" c 

### from long-term records at the most downstream gaging station on each river lV.S. 

### Geolollical Survev. 1977). The inflow contribution from ungaged areas was approximated by a proportionate increase based on drainage area ratios. Inflow was entered at appropriate cells near

... .. 01. .•

... " VI ... " ULVU"I.



### Once-through. cooling-water systems of power- .e;eneratin)!; stations were handled in a similar wav. Cooling-water intakes were simulated as negative discharges at cells close to the locations of intake structures. Cooling-water discharges were simulated as positive

.1, .11 •• 1. •**,_~"'~ ~.** **~"'** ..**~.~~'" .~**  ... '" ..**"'~.** 1 .. 

### of the Tampa Electric Company (oral commun., 1975) indicated that typical cooling-water discharge rates for both the Big Bend and Gannon stations (fig. 1) were 1,960 ft 3

### /s. Information from a Florida Power Company representative (oral commun., 1975) indicated typical -'

## . 

# ...**~~~~..** 

# .**~-** 'a."1 la."" "'''I'' '.vvv 1L "IVI VVLlI the • .**~nti** .. •**Tc:l~nti** (fil1 1\ Seaward Boundarv 

### Fluctuations in tidal stage, the primary force causing time-dependent water motion, were applied at the

• nf th
......nti
..l Th
...... nti
..l , 

### water to and from sections ofthe estuary by solving equations 1, 2, and 3 for each designated time and space increment. At the seaward boundary. velOCIties were com-


## .. pUU::U oy USIng llli:ll UIU 

### not require any information outside the boundary. This proceaure proaucea less precise computations at ana near 

# .. Lilli:: Llldll dL ULIlli::1 

### Because of less precise velocity computations and in-

.. ilitv of the simnlified eauations to numerical instability, the seaward boundary had to be established some distance from areas where model results could be significant and where large depth changes could

• .• • • T IIlUU"'li:: VI L"" " ap

### proximately 4 mi offshore from Egmont Key accomplished these two objectives. To generate offshore tidal conditions, a cross-spectral analysis technique described by Leendertse and Liu (1974) and used by Van der Ree and others (1978) was applied
.• .J ". n. ..... ("0 .v .....a.-".a6'"
.. u."-"" .. ",, ........ IVI .. vn**~'" u.,,.~**  

### (site 22. fig. 8) to the seaward boundary at location WC-154 (site 24. fill. 8). The technique required concurrent time-series data at each location to define crossspectral relations. Once established, these relations could then be used to generate time-series data at site 24 for

• ..I ,,_ ,.1..' ..I " 1::'
....**T'\~ C'~.~**  ....,**P"'''~~ .~.**  •... ..**~....."'.~ ~,**  ..**~. ~~** **.~.**



### Concurrent time-series data were available for the period January 25 to February 11,1979, when offshore pressure recordings were obtained by Woodward-Clyde Consultants (1979) and when the Fort De Soto gage was in operation. A part ofthe concurrent data (fig. 9) shows

• • . L •**~~** .... 1..

### ~ade to the Fort De Soto record, are shown in figure 10 and compared with measured data. The standard error between measured and computed data IS about 0.1 

## n. The tide conditions that existed in 

### the GulfofMexico during a period ofintensive field measurements in Tampa 'R",,;n 10'7') Ul
..r.. . h" lldnl1 I"rnc:c:_ •

., 

### relations. Computed results are shown in figure 11. Because additional information on tidal conditions in the GulfofMexico was not available, the computed tides at sire**~4** 

### were apPliea along me emire seawara Table 3. Average annual discharge of streams tributary to Tampa Bay (U.S. Geological Survey, 1977)
Tamoa Bav

subarea "'''''0'

TYO n: 

## .. ----- ------ --- -- - - --- Alafia River

_ Total of several small streams

_

.... .r "0 discharge (cubic feet per second)' 459

99
11"7 Middle Tampa Bay Little Manatee River

_ Lower lampa nay AIVCI

_ __ _ _ -____ -- -- -------- Total

-------------------

1All values linearly adjusted to include effect of ungaged drainage area. 240 1,904

Model Development and Application t 7_ (:'L'" 'U '" '" BEACH 

# 7A

\ 1ST. PETERSBURG \:

\

# ~20 

# ,J_ 

# \**~;.** J \ " 

# I PASS-A-GRILLE 

### lW I
...**~~~lE** 

# 'I I I _0' , lJ 

### 0 to I 12 ,.. EXPLANATION TIDAL STAGE GAGE AND**~II** t SUBMERGED PRESSURE RECORDER**I~U.:>** 'fU WOODWARD-CLYDE CONSULTANTS, 1979) TIDAL CURRENT SITE AND SITE

"," SKYWAY!i" '" EGMONT 

# v· 2 

# 3... ------**II·-~~** SHIP CHANNEL CHAN:EL FORT •**Y'~,** ""I' '\\ // <:r)lIT" - 

# • NUMBER NATIONAL OCEAN SERVICE LONGTERM T**~II t~TE**  NUMBER (FROM DINARD' 10711\



### \

# ~--~~**~NNA** MARIA -

_

## :,./"~

# ~a V \ 0 1 2 3 4 5 MILES
Figure 8. Location of tidal stage and tidal current measuring sites and submerged pressure recorder and long-term currpnt <itoO< In Tampa Bay.

18 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida4



# ........ GULF OF MEXICO (WC-154) TAMPA BAY AT FORT DE SOTO
..J 

### « Z ? & ::::' 

# r. t- 

### « ." Z N 

# .. ." 

# , ·i 

# .. . w**,~** 

# - al :::!: ol ::l 

# ,.
.. :

# . w Cl 

### :0. 

# li. V**'~** 

# A fA 

# li 

# N f* > ..J 

### • # 

# • o « 0t:*" 

# 1'..


# - . ..' 

# - t- 

### ffi 

# , III \ 

# -' ,. 

# ., J J 

# . • 

# . w 

# . ." 

# - y fI 

# )j 

# . JJ u.. u 

# ,. 4 

### z i= 

# • I _," 

# . - W 

### • 

# , 

# .- W 

## 0**.~** 

# .. .\} 'J 

# • .\J w 

# - 

# .. . - 

# . :U 

# .. # 

# . (/) 

# • 

# . t 

# .- . ..J -2 

### « !:::'! t-

-4 I I I I 

## I I I I I 

## I I I I I I I I I I I I I 0 50 100 150 200 250 TIME. IN HOURS Figure 9. Comparison of observed tidal stage in the Gulf of Mexico and at Fort De 50to inside the mouth of Tampa Bay. Locations of sites are shown in figure 8. 

### for the model calibration and verification periods shown 7 and were applied to spatially averaged wind fields deterin figure 11. mined from hourly observations ofwind speed and direc-



## .. IIUt: uunng tnt: peuuu wele llUll IUCiue Cit 

### sues III tne I Cllllpa Day alea. llle chiefly dirunal and had a tidal range ofabout 2.4 

### ft. The sites used for this purpose include the Tampa Internan1 ri",' Me tirl
.. Ul!'!" !'! hnllt 11'\ hnllr" Th
.. tinn!'!1 '**~.** Air Pnrr.. 'R!'!"..**~t** 

# - of falling tide was about 9 hours. The first verification Clearwater International Airport Sarasota-Bradenton period also had a predominantly diurnal tide that had a Airport, and Albert Whitted Airfield (fig. 1). range of3.6 ft. The second verification period had mixed The wind field was computed by averaging hourly or-


# . . . . 

# . .**~.** 

### llue cUIU**lCll~e** • J. 

### Ht; 11Ulll lllt;llt; 11v

### t; IlHt;Il, HI**a~-** 

### diurnal tidal range was 3.0 ft. The three tides are repre- cordance with equations 13 and 14: sentative of conditions in Tampa Bay. Water-Surface Boundary 

### Wx

## =

# t LW; • sin<Pi (13) i= 1 

### I ne water surlace is tl eateU all a 

### verdl;auy 

### , • •**1.~** ••**:~~** • • 

# . . 

# ..- .., 

# .- S stresses transmitted to the flow, depending on wind speed 

# - IE and direction. Wind-shear stress components at the air- 

### Wy 

## = <" Wi • COScPi (14) water interface were computed by using equations 6 and i= 1 Model Development and Application 194 N Ol u.. 0 

# ......... COMPUTED ::E OBSERVED 0 ....J 

### « a:: L 

# f w > J, w 

# 1 0 

# • t;:i 

## ,... 

## It 

# Il 

# • 

# A c.:l ....J 

# IJ « 

# .. 0 

# (\4**~'** 

# f

# A.~ 

# tJ
. F 

## 1\ 

# It i « o**f-~** 

### z 

# .- l!i 

# , f\ \j 

# , J J 

# ... \/ ::J 

# \) 

# .. 

# V ., w ell 

# \J a:: 

## ,... 

# • 

# , w 

### W ell 

## V «

... U W u..
,;i (J) ....J 

# I I I I

-4 I I I I I I I I I I I I I I I I I I I I 0 50 100 150 200 250 TIME, IN HOURS 

### Figure 10, Comparison of observed tidal stage in the Gulf of Mexico with tidal stage computed by using cross-spectral procedure (described by Leendertse and Liu, 1974). 

### where 4> 

## = spatially averaged wind direction, in degrees 

### Wx=x component of spatially averaged wind clockwise from north.



### - speeu, in miles per nour; The computed wind field was assumed to be vanable 

### Wy= 

### Y component of spatially averaged wind with time but spatially uniform over the modeled area. s.need in miles. ner h01lr' • ...I ,I. , 

### Wi 

## =hourly wind speed, in miles per hour; and 

# .... ....

# - were dmi1<lT 

### no larae error due to s.natial averal!'inl! is 

### 4>i

## =hourly wind direction, in degrees clockwise expected. Wind speeds were generally within ±2 knots, from north, that the wind is blowing from. and directions within ± 30 degrees, of each other. ExThe results were reconstituted by using equations 15 and ceptlOns occurrea pnmanly aurmg rapla wma Shilts 16 to produce average hourly wind speed and direction associated with the passage of cold fronts. Wind speed over the study area: and direction during calibration and verification periods -;;;: f-.rr -;;;:**~"I\** • "


### ...

### , ::Ire s.hown in fil!'1Ire 12 rr 

### \.. x y) 

# '£ 07 1 

### Wind during the calibration period was initially light,



### - about 5 knots from the east, became calm by the end of

_ <lTf't<ln 

### W. (Hi\ u'/' 

### 20 hours, ana plckea up trom the west aunng the last


# - , 

## . 

# .... ,. "**~'** 

### y

.. UVUl;) VI • yv lUU ;)jJ
.... U UUIU15 .U<; 111;) • 

### where verification period averaged about 6 knots. The direction 

## w 

# ... wind sneed in miles ner chanlled at a uniform rate in a clockwise manner starthour, and ing from the east-southeast, through north, and around 20 

### Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida4 Q) •••••••• GULF OF MEXICO N TAMPA BAY AT FORT DE SOTO 0


# - :5 I- 

### « 0 ...J A 

# " « 

# • i= 2 

# 1 YI**,~** a: 

# l\ 

# ,., w 

### _'\ > u 

# l**1~14** i= 

### 0 

# J 

# I ) 

# I yJ :. 1 

# f\j 1 ••

# , 1\ J 0 Iw 

# =Ai t=l ...J 

# I I I 1 1 • 

### « • • 

# ;\ z 0 L:: .J 

### « v 

# 1**~t** 

# !/ 

# "J 

# - z 

### • • 

# , .... l

## .~ 

# , " • 0 I.**.~** ...J 

## U ,\l 1-

## :~ 

# .. • a: 

# .. 0 

# . 

# - . • w > 

## • 0 CZl 

### « 

### tu- 2 w 'A ,IIUN FIRSt Z PERIOD mN IIUN v u.i PERIOD PERIOD t=l 

### « l- (/) ...J 

### « 0 i= I I I I I I I I 4 24 25 26 27 28 29 30 31 1 2

JANUARY 1972 FEBRUARY 1972 IIIVII:,**II~** UA T;:) tlgure 11. 

### Lomparlson OT 

### computeo tloaJ stage in me LJUIT or 

### Mexico wim UU31:"1 ,"",u**Liu~** dL rUIL**LJ~ ~ULU**  uurifllS II IVUI:" I 

### carioration and verification periods. the points of the compass to reach north a second time. starting water level at the seaward boundary. CorrespondWind during the second verification period began as ingly, all tidal currents at the start ofeach model run were calm, then averaged about 7 knots from the south- zero. The bay was motionless. southwest tor most ot the penoa. Operationally, about 12 hours of real time must be 

### Initial Conditions simulated before the effects ofthese assumed initial conomons Olsappear Hom me SOludon anu oeIOre mooel Establishing initial conditions is necessary to define computations accurately reflect real stage and current three time-varying parameters-tidal stage, tidal current, conditions. Circulation computations are more sensitive and constituent concentration when**startin~** 

### model n ... rl "f ..,h""t 

# "A**~f ~anl**  t; ..... A 

### computation. The following sections describe how these 

# -. before the effects ofinitial conditions disappear. Model initial conditions are assigned and how they affect simula- comoutations durin.!!: these periods are disre.!!:arded. If 

### a dUll n:SUllS. 

### model run is restarted to extend a previously simulated Tidal Stage and Tidal Current 

### period, initial tidal stages and currents for each cell are A level water surface was assumed throughout the bay read from a restart tape created bythe prior run (see fig. at the start ofeach model run at an altitude equal to the 6). Model Development and Application 21water can cause rap1 egeneratlon 0 compu e concenFurther description ofturbidity plume simulation is**give~** below in the section Calibration and Verification. ing the seaward boundary during floodflows.

The initial concentration used for calibration ofmodel allows reasonable computation ofconcentrations to continue at the seaward boundary through all phases ofthe tide. This procedure is considered to be more realistic than model allows a gradual return of concentrations to an initiall defined value. This rocedure is a roximate but



### Calibration and Verification dispersion was a constant, near-zero value for turbidity. tions can be brought from outside the modeled area. This

31 30 Z9 21 TIME 24 25 26 JANUA Y 7Z

Constituent Concentration Table 4 shows starting and ending times for the calibration and verification eriods and availabilit offield data for comparison with model computations. Tidal current data were not available for January 24 and 25, 1972; as a result, calibration was based on stage data only. Stage An initial concentration must be assigned to each cell for each constituent included in the computation. periods. specifying a default value; (2) the default value can be changed at one or many cells by specifying values that override the default value; and (3) a complete array can be provided that defines the initial concentration at each cell. Tidal Stage Tidal stage data were measured at 14 locations (sites 10-23, fig. 8) from June 1971 to December 1973 (Goodwin and Michaelis, 1976). Table 5 gives the site number, the downstream order number, the complete station name, and the latitude-longitude position (progressing

ments that measured water-level altitudes every 5 or 15

. . r cure station) for tidal stage stations 

### in Tampa Bay. Each of the 14 stations was equipped with digital recording instruuseful when simulating the spread of dye or other constituent injected at a point. Overrides can be used to advantage 1 one or more sma su reglOns are nown to v s/mo. Gages were referenced to the NGVD of 1929 by



## . .
o t e mo e are compute rom v ues at mtenor pomts lated region. An array is normally provided ifan accurate



## . .. of a model run. Constituent concentrations at the seaward boundary ing unassigned and uncomputed constituent concentra- vals during the last 24 hours of simulation ranged from
Table 4. Calibration and verification time periods and field data availability for tidal stage and current observations in Tampa Bay, 1972
Period Start End Duration Field data availability
First verification

_ 1-27-72 1205 1-28-72 2400 36 Yes Yes

econ veri ica io 22 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaTable 5. Information summary for tidal stage stations in Tampa Bay r, ,rr-r downstream Station identification' North West (see latitude longitude fig. 8) order no. 10

___________ 02-3000.72 Tampa Bay at Anna Maria

______________________________________ 27°32'03" 82°43'50" II

____________ 02-3000.85 Tampa Bay near Terra Ceia (South Skyway)

_______________________ 27°35'30" 82°37'45" 12

____________ 02-3000.88 Tampa Bay near Piney Point (Port Manatee)

_______________________ 27°38'06" 82°33'32"**I~U1P~ D~Y** **1~~1** AU'Aiu lAPOIlO**~eacn** ____________________________**l~** ____________ u<.- .)V\J.).ov**"'I-'+O·~I** 0<' <.j j.) 14

___________ 02-3017.61 McKay Bay at Tampa

__________________________________________ 27°54'54" 82°25'25" 15 02 3060.32 HilIsborouszh Bav at Ballast Point at Tam"" ':)70**~~'.,.,"** R.,0.,R'<17"



### - 'L ""**~,,£** nn r\' T. n**~.** .......**,'~** ...**'~nll** 

# - '--If



### --- .. -, "r' 

### --- 

### -**~. ~J**  0<' .).) j 17

___________ 02-3075.78 Old Tampa Bay at Safety Harbor

_______________________________ 27°59'17" 82°41'07" 18

___ 02-3077.69 Old Tampa Bay near Bayview

__________ 

## --------- ------- 27°56'28" 82°43'15" 19

___________ 02-3079.30 Old Tampa Bay at Gandy Bridge near Tampa

______________________ 27°52'46" 82°34'57" 20

___________ 02-3080.82 Tampa Bay at St. Petersburg

____________________________________ 27°46'24" 82°37'25" <'1

____________ U<.-.)UO' .<.V**I~UlP~ D~Y** **~,** .:>Uu.ui"c**~lI.yway ~rioge**  near**~[.** relersDurg <'/·.HUO lS.l-4Vl.l' (North C;:\'"",,,,,\ 22

___________ 02-3086.00 Tampa Bay at Fort De Soto Park near Pass-a-Grille Beach

___________ 27°36'53" 82°43'33"**.,~ m-lORfi.~O**  P" ...**".Gri11~** Ch"nn,,! n.."r p" ...".nrm.. R"",.h .,7°<11'1/y'**".,OA~'A""** 

### - --- 

## ---------- 24

___________ 

### - Woodward-Clyde gage number 154 offshore of Egmort Key (WC-154)_ 27°36'12" 82°51'54" 'Underlined name is shown in fig. 8. 0.03 ft at South Skyway near the mouth of Tampa Bay, computed tidal stages for the first and second verificasite 11 to 0.13 ft at Safetv Harbor site 17 and**B~vview** tinn •**~rp** I:hnum in fiollrpl: 1.<1**~nn** I.e:: . -r site 18, in Old Tampa Bay (table 6). The average stand· Iy. Some difference between observed and comouted ard error for calibration was 0.07 ft. Graphical compari- stages is to be expected since all model adjustments were sons between observed and computed tidal-stage water designed to make model computations match calibration· 

# .**~.** 

# .. periou neJU VV,""'l as ClOselY as**posstore.~- ~JVJ**  :11.11. BVlU lil\; lUVUIU IV IU\;**U\;i:lU~** bay are shown in figure 13. From the graphs it can be justments were not made for verification periods. That seen that about 12 hours of real time must be simulated the standard errors are about the same for all three before the effects ofassumed initial conditions disappear periods lends credibility to the model's caoabilitv to ac· and before model computations reflect real stage and cur· curately simulate real conditions. rent conditions. Tidal Current 

### ....., L' 

# . 'M .1 

### 11'" _'" <;l1Vl lVl lIVlll \110",' (1- (10 ft <Inn th
.. r<lno,," U1<10 frnrn (I {)A**.~** () 1 C 'T':--1_1 

## ...

# _.- • ,,+**~:+_~** 1 0 ,,--- -**-~ ~,**  "'" '7 ft (table 6). Graphical comparisons between observed and 25 to 31, 1972 (fig. 8 and table 7). Instruments used were Table 6. Standard error of tidal stage in Tampa Bay for calibration and verification periods Site no. Standard error (feet)

(see :,rallon name First Second fig. 8) Calibration verification verification 10 Anna Maria 004 0.09 o l() 

### - 

### - - 

### - - ---- -- -- - - 

### 11



## ------------------ South Skyway

_________________________ .03 .07 .08 12



## ------------------ Port Manatee



## ------------------------- .04 .04 .04 15



### ------------------ Ballast Point

__________________________ .06 .07 

### .11 1" RnC'1<v Pnint 11 11 n"7 17



## ------------------ Safety Harbor

_________________________ 

### .13 .15 .10 18



## ------------------ Bayview



## ------------------------------ .13 .15 

### .11 

## .- 17 

## ------------------**~<tuuy D11U~~**  

## _==

__=_=====

__==

__==

___== .Vll**.l~** .W '0 {)C {)J; no 21



## ------------------ North Skyway

_________________________ .04 .06 .07 22



## ------------------ Fort De Soto

__________________________ .04 .06 .07 Average


### - ---- 

## ------------- .07 .09 .09 Model Development and Application 23SAFETY HARBOR SITE 17 GANDY BRIDGE SITE 19 3 3



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# _._- Figure 13. Observed and computed tidal stage at selected sites in Tampa Bay during calibration period.

24 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaSAFETY HARBOR SITE 17 GANDY BRIDGE SITE 19**~~** 

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OBSERVED ............... COMPUTED TIME. IN HOURS Fil!ure 14. Observed and comDuted tidal stalZe at selected sites in TamDa Bav durina first verification neriod.

Model Development and Application 25SAFETY HARBOR SITE 17 GANDY BRIDGE SITE 19 " 

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3 0 6 12 18 24 30 36 "0 6 12 18 24 30 36 OBSERVED ............ COMPUTED TIME, IN HOURS Figure 15. Observed and computed tidal stage at selected sites in Tampa Bay during second verification period.

26 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaWater surface

I / I I I I I I I I I I I I I I I I I I I I "- I
... I
.... 

### .... I
.... I
....

scn sphere Magnetized

buoyant rigid rod Horizontal angle,8 Midtide depth=D

bay bottom

Site no. North West 

### and direction of flow. 1

_ 2 3 27°43'01" 27°42'54" 27°42'59" 82°36'04" 82°35'18" 82°34'25" 

### the average velocity in the vertical. The center of each meter was placed at approximately four-tenths ofthe midtide water depth from the bottom of the bay (fig. 16). 5

_ 6 9

_ 25 Ross Island

_ 27°42'42" 27°42'39" 27°50'57" 27°49'54" 82°32'28" 82°31'45" 82°34'47" 82°34'12" 1 

### a current ata co e eye in i ardi, 1978) showed velocity profiles typical of vertically

Model Development and Application 27

### Errors in the measurement oftidal currents were due Measurement error for tidal current direction ranged rent meters and 2 the visual-manual data r n lin procedure needed to digitize the data. Visual interpretation errors between scribed lines on sequential frames of p otograp IC I m were approxImate y ort e mc mation angle, ¢. 

### The error ranged from 1° to 9° for the horizontal angle, 

## e, based on the range of¢, 

### as follows: current speed at sites 7 and 8 in Hillsborough Bay helps explain the high standard errors for direction at these sites (ta e 8). DIrection errors also could have resulted from inability of the model grid size (1,500 £1) 

### to adequately resolve details ofmany channels, islands, and submerged Range of inclination Translation error of horizontal angle (8), 

### are considered to be representative ofreal conditions but less accurate than in other areas of the bay. Di r i n



### 7. Errors associated with the residual currents at these for the horizontal angle. Measured tidal current, therefore had an overall error of about 0.1 ftls at velocities
reasonably simulate the shape ofthe observed plume was Costs ofmodel operation precluded making a separate run devoted exclusivelyto plume analysis. Therefore, the the model. Satellite imagery of a turbidity plume caused by

image is rectified and superimposed on the simulated plume in figure 19B. 

### The barbell-shaped plume is unique to tidal waters and depends on the relative timing oftur-



## . . 3 1 11 

### to 20 

### 21 to 90

ficient to compute a long-term residual current. Locations ofthese sites 25 and 26 are iven in fi ure 8 and table sites are not known. According to Cheng and Gartner (1985), uncertainties exist when computing residual curof less than 0.5 ftls and greater than 1.5 

### £1/s. Between these bounds, the error is about 0.03 ftls. Tidal current data collected over a 30-day time period

ner (1985) were able, however, to demonstrate close agreement between two independent methods for computation ofresidual currents in South San Francisco Bay. They concluded that satisfactory residual computations could be made from tidal current measurements. primarily for tidal stage and tidal current verification. The simulated tidal range at St. Petersburg, near the plume, was 3.1 ft (fig. 14), and the actual range at St. Petersburg that produced the observed plume was approximately 1.9 ft (U.S. Department of Commerce, 1971, p. 129). the second verification period. Tidal currents were not measured during the calibration period. Graphical comparisons between observed and computed tidal currents (both speed and direction) for selected sites are shown , w 

### d= 25 (J. J. 

### Leendertse, oral commun., 1980).

Tidal stage and tidal current (at the simulated dredge site) and the period ofturbidity generation that were used to simulate the turbidity plume are shown in figure 20.



## . .. range from 0.08 to 0.17 ftls, with an average of about 0.11 ftls. Standard errors for direction range from 5° to 25°, with an average of about 14°. With a fewexceptions, these comparisons are very good and provide additional assurance that the model simulates real series of six illustrations in figure 21 follows plume development at 1, 5, 9, 13, 17, and 23 hours after start ofturbidity generation. Figure 21A 

### shows a nearly circular plume at high slack tide. An elongated plume is shown during maximum ebbflow in figure 21B. 

### Figure Measurement error for tidal current speed ranges from about 0.03 to 0.10 ftls for the currents encountered.
more 0 

### e compu e s an ar erro. e error is attributed to local conditions that were not adeMeasurement error, therefore, may account or ha or

28 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaSITE 2 SITE 4 500 500 450 

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## . -**~.** I" 0 0 10 20 30 40 0 10 20 30 40 TIME,IN HOURS COMPUTED ---------_ .... OBSERVED Figure 17. Observed and computed tidal current speed and direction at selected sites in Tampa Bay during first verification period,

Model Development and Application 29SITE 2 SITE 3 500 500

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30 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaTable 8. Standard error of tidal current speed and direction in Tampa Bay for verification periods

First Second First Second verification verification verification verification O.Og 17

.09 0.12 5 8 .09 .12 g 10 .08 8 .12 9 .15 .16 16 16 .10 .10 17 17 .10 .08 25 22 .13 .17 14 13

-- -- 

### - -

.10 .12 13 14 Site no.

(see fig. 8) 1

_ 2 3 4 5 6 7 8 9 Average

_ Tidal current speed, standard error (feet per second) Tidal current direction, standard error

(degreesl



### B DREOGE



## , , 

## , , , .' \ ., ,0 EXPLANATION , 

# O \..--SHIP CHANNEL SATELLITE , 2,1**A~** IMAGE PLUME \ ':,':", SIMULATED SHELL \ 

### ',1/1',;, PLUME

(I) 

### vertically averaged tidal currents used in the simulation and (2) faster near-surface currents in the bay that carry suspended-sediment particles constituting the observed turbidity plume. Simulated and observed plume lengths can be compared by adjusting results shown in figure 19B 

### for the effects of different tidal ranges and different current speeds. The length of the simulated plume (measured from the shell dredge to the centroid ofthe southern end were not available for suspended-solids concentrations within the observed plume. In spite ofthese drawbacks, the model did reproduce plume characteristics. The area bounded by the 75-mglL line ofequal suspended solids concentration in figure 21 C is reproduced as the simulated plume in figure 19B. 

### The observed and simulated plumes in figure 19B

### show nearly identical shape and orientation. The southern end of each plume has a large bulbous shape. The northern ends show less bulge because oflimited dispersion time. A narrow section that follows the ship channel connects the northern and southern ends ofeach plume. The only significant difference between the observed and simulated plumes is their lengths. One factor causing the length difference is the inequality oftidal ranges (p. 28). Another factor affecting plume lengths is the difference between 

### A Figure 19. A. Satellite image of turbidity plume in Tampa Bay. B. Comparison of satellite image and simulated turbidity plume.

Model Development and Application 31'" 2.5 2.5 N 0
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### o 6 12 18 2. 30 36 TIME. IN HOURS Figure 20. ndal stage and tidal current used during turbidity plume simulation. dredging (1972), and postdredging (1985) levels of development. The following sections defme the bottom configurations, boundary conditions, and initial conditions used in each application. Bottom Configurations

The bay shorelines and areas of bottom changes for 1880, 1972, and 1985 are shown in figures 3 and 4. 

### In 1880, the bottom configuration was characterized by gradually varying depths in most parts of the bay. Notable exceptions occur at the northern end ofEgmont Key and at the mouth ofOld Tampa Bay. Several islands existed near the mouth ofTampa Bay and at other locations around the bay periphery. The 1972 bottom configuration was characterized by broad areas of slowly changing depths interrupted by extensive manmade linear features, charmels and islands, aligned perpendicular and parallel to the major axis of the bay. In 1985, the bottom will have additional physical changes that 

### will include large disposal islands in Hillsborough Bay and more extensive submerged mounds along a deepened and widened ship channel.

This compares very well with the length ofthe observed plume, 4.0 mi, as measured from figure 19B. The general agreement between observed and simulated turbidity plumes indicates that the dispersive features ofthe model adequately simulate actual conditions. ofthe barbell) can be adjusted for tidal range differences by assuming a linear relation between plume length and tidal range. The simulated plume can be further adjusted by a proportionality factor relating vertically averaged tidal current speed to near-surface tidal current speed. The factor lI6ed was determined from velocity data presented by Dinardi (1978, p. 33) at two sites very close to the plume location. Surface waters in this area apparently move about 

### 23 percent faster than the average speed in the water column. The following computation gives the adjusted simulated plume length: Actual tidal range Speed 

### x Simulated range 

### xcofrrection actor Simulated length (from

fig. 19B)

5.2 mi 1.9 

### x-x 3.1 Adjusted 

## = simulated (17) length 1.23 =3.9 mi Boundary Conditions Ofthe three types oftides that occur in Tampa Baydiurnal, semidiurnal, and mixed (fig. 2)
- the most prevalent is the mixed tide that has two unequal high tides and two unequal low tides during each cycle. Therefore, a mixed tide was chosen as the open-water boundary condition for model application. A mixed tide similar 

### to that measured during the second verification period (fig. II) was used as the repeating tide (fig. 22). To simplify analysis of results, the tidal period was adjusted to 24 hours (an even multiple of the time step), and small irregularities in the second verification tide were eliminated by assuring smooth first and second differences in tidal stage (table 9).

Because it was considered least likely to mask tidal flow, circulation. and flushing changes, a zerO wind condition 

### was used for all model applications. Changes in flow, circulation, and flushing due to wind were beyond the scope of this investigation. Freshwater river inflow was held constant for each model application at the average annual discharges listed in table 3. Cooling water used by power-generating stations was treated as described under model development for 1972 and 1985 levels ofdevelopment (p. 17). There were no power-generating stations on Tampa Bay in 1880. 

### Application to 1880, 1972, and 1985 Levels of Development

The model, after calibration and verification, was applied to determine flow, circulation, and flushing characteristics of Tampa Bay for historical (1880), preInitial Conditions Tidal currents throughout the modeled area were assumed to be zero at the start of each model application. Tidal stage throughout the modeled area was initially constant at the National Geodetic Vertical Datum of 1929. 32 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

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### ~t.--.. 

# , 

# .ood; 

# fr N I 

# fJr f N \.. f \.. 

# .J J:J::t f</ 

# \ f 

# K_ f ./

# 5~1S!J 

# ;V 9 

### , 2 3 

### • 5 " 

# ;Va , 2 3 

### • 

# • , I 75 MllES MILES C. 9 hours after sta
. F. 23 hours after start. EXPLANATION -TOO-Contours show lines of equal computed concentration of suspended solids, in milligrams per liter, with a simulated injection rate of 15 cubic feet of suspcndable material per second (Gren, 1976).

.**-~ .~"**  

# .. . .u 'U' ." ... , 'a, '"**,~,** , 

### .",

r' 

# - M 

### . .**+:~ ~r** **r+~r+ ~.**  .. 

### "6"''''''' . JII"tJ'" VI lUI VIUI.y f-JIUI <;; '0 <>

Model Development and Application 33Table 9. Stage, first difference, and second difference of repeating, 24-hour tide in Tampa Bay used as boundary condition for

....**"'rl~1** ..**r"'~~a ,,~I**  .._••**_I~,:.,a .~**  

### . 

# . .P**'~~M** 'T First Second First S;sond <:hno ,.1:«0._**..J:u~._** c.- ._**..J:U~** lime lime ·0 (feet) ence ence (feet) ence ence (feet) (feet) (feet) (feet) 0000


### -------- 0.00 0.23 -0.02 1200


### -------- 1.67 0.13 -0.03**~~~~** 

# - vV.JV -------- 

# ..... ..... .V.:l I':'.:lV

_ 

### --- L .IV .UJ 0100

-------- .39 .18 

### - .03 1300


### -------- 1.84 .07 

### - .03 0130


### -------- .54 .15 - .03 1330


### -------- 1.88 .04 

### - .05 0200



### -------- .66 .12 - .04 1400



### -------- 1.87 

### - .01 - .08 0230


### -------- .74 .08 

### - .05 1430



### -------- 1.78 - .09 

### - .08 0300


### -------- 

### .77 .03 - .08 1500



### -------- 1.61 - .17 - .08 0330


### -------- .72

- .U:5 - .05 1530


### -------- 1.36 .25 .05 0400

------- .62 

### - .10 - .03 1600



### -------- 1.06 

### - .30 

### - .03 04":\0 .49 .13 00 It;10 71 .":\":\ 11'7 

### -- U'UU

________ .JO .1J .UJ l/UU

________ .Jll .J' 

## .oz 0530



### -------- .26 

### - .10 .03 1730


### -------- .01 - .37 .00 0600


### --- -- - .19 

### - .07 .03 1800


### ---- - - .36 - .37 .03 0630


### -------- .15 - .04 .04 1830


### -------- 

### - .70 - .34 .06 0700


### -------- .15 .00 .05 1900



### -------- - .98 - .28 .07 0730


### - 

### ---- .20 .05 .04 1930

-- 

### ---- -1.19 

### - .21 .07 0800

-------- .29 .09 .04 2000


### -------- -1.33 

### - .14 .08 0830



### -------- .42 .13 .03 2030


### -------- -1.39 - .06 .09 nonn (Q 1,;;**n~** ",nn ,**~£ n~**  '" 

### ---- --- 

## . '" 0930


### - ----- .77 .19 .02 2130


### -- - -- -1.23 .13 .08 1000

-------- .98 .21 0 2200


### -------- -1.02 .21 .06 1030 

### l.1Q 21 fI'7 '7'71f1 7( '77 nn 

### - --- - 1100


### -------- 1.38 .19 - .03 2300



### -------- - .48 .27

- .02 1130


### -------- 1.54 .16 - .03 2330


# -------- - .23 .25 - .02 2 

### • 

# /\ • 

## -. 

# i\ • • 

# i\ -. ...J 

### « Z 

### 0 

# / 

# \ / \ / \ .:::: N 

# / \ 

# \ / 1**~~** 1

# - -**g~** 

## \**al~** 

# (\ 

# / (\ (\ 

# / , a::::>**o~** >0 

## V 'J 

## II V 

### II V 

# , ;::., al 

### « v 

## \ 

# , «u

..... 1= 

## J 

## J J wa::

w**~>** 

# I I \/.**z~** 

# \ \ - ..... w·w t!:l 0 -1 

# • «0 r.nt!:l 

# V 

# V 

# V ;J. 0

..... -2 

## • 

# • • 2400 1200. 2400 1200 2400 1200 2400 TIMF IN**I-InllR~** Figure 22. Repeating, 24-hour tide used as boundary condition for model application. 34 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

### To help determine changes in the flushing rate of Note that

- 

## B is the same magnitude but of opposite Tampa Bay between 1880, 1972, and 1985, a representa- direction to B. tlve constItuent dIstnbutIOn, measuroocrunng JUlY 1'J " 

### Water and constituent transportounng Hood and ebb and reported by Goetz and Goodwin (1980), was used. conditions at each cell in the model are computed as the**'T'1..~** • .**{r.~ "'~\'**  .1... ., 

### " 

## . ,.**"1..~** ...**:~ ".~.** **.~** 

# . -0 v. ".... '''''''.v,,, ... un",. 

### _u, _. u, source of phosphorus existed along the eastern shore of figure 

### 25A. Averaging avoided overemphasis of possiHillsborough Bay in the vicinity ofthe Alafia River. Con- ble short-term, local oscillations. The direction of the centrations ranged from 1.5 to 2.5 mg/L in Hillsborough summation vector defines the direction ofthe average vectlay, were nearly constant at U.l:S mg/L m Uld umpa tlay, tor. The magnitude ofthe average vector IS one-sIxth the and decreased to less than 0.2 mg/L at the entrance to summation vector. ...., R"" T">'- •**U'~.~P** 0**~~,l** 

# .. "rp 

# -. 

# -. -0. 

### Tamna Bav were 10 to 100 times I1:reater than that of 

### rp<;:idual-transnort vectors at each hypothesized as needed to maintain primary productivi- cell. The computation is shown schematically in figure ty (photosynthesis) in this area ofFlorida (U

### .S. Depart- 

### 25B. For a repeating, 24-hour tide, such as given in figure ment 01 

### the Intenor,**I~'I,** 

### p. 24). 

### At these elevatea con- 22, the summation of 288 5-mmute transport vectors IS centrations, phosphorus is a conservative (nonreactive) actually computed at each grid location. Twenty-four**~,,'** "nrl**;~ 11~pfll1** **,,~** " tr",",pr**11.~"p** ,L**'-1..~p~+,~p~l~p:** .... Thp 

### lllC'k of' -r 

### thp <;:tllrtinl1 noint ofvector 1 and the ending point of vector 24 indicates a net or residual 

### MODEL RESULTS AND ANALYSIS transport equal to the summation vector at that location. Magmtudes 01 

### resIdual-transport vectors are generauy The results of model computations presented in this one to two orders ofmagnitude less than those oftypical section are largely dependent on using vector maps that flood- or ebb-transport vectors at any location. visually represent water and constituent movement computed at each cell of the model. Vector transport sym- Transport-Change Maps bois (representing the directional flux ofmaterial, either water or constituent passing mrouglreacITmuucll,;CU) i:1IC , 1 

# - '0 

### 111<1p:> '0 .v ...."**~.** •..
" •. -l**+'~_** 0**~~,l** •**~+'** •**rp~, Ilt~**  fnllnm;na o • 

### tn Hnw 

### mllC'h llnt! what Darts of



# - - 

# ... The flux ofwater, in cubic feet per second, is described Tampa Bay have undergone significant transport changes in this report by the specific terms ebb, flood, and residual between 1880 and 1972? and (2) How do these changes water transport. The flux of constituent, in pounds per compare with those expected between 1972 and 19l:S5'! The second or pounds per day, is described in this report by symbol plotted at each cell location on a transport-change the specific terms ebb, flood, and residual constituent map represents a difference range (in percent) between

• fnr hun 

### levels of 'r --. 

### Analysis ofmethods to discern differences in 

### tidal flow, development. circulation, and**flushin~** 

### among the 1880, 1972, and 1985 Percentage differences at each cell are computed as 100 levels ofdevelopment is dependent on some concepts of times the magnitude ofthe difference vector (A
- tl) m vector anthmetIc. The methoas usee are aescnoea m o 0 0 n 

### llgure ;l4L:, 

### OIVIaea oy-me- UI Ult;**Vt;\';~UI** 

### some detail in the following section. associated with the earlier level of development 

## (B), or 

### I A H 

### I X 

### 100 

## = percent change in transport (18)

O. 

### • 

## I B 

## I This technique recognizes that changes in transport direcVector Computations tion are often as important as changes m transport magnitude. Directionality is inherently incorporated in- 

## ,-. 

# - • npp£1 nnt 

### f\.ooition anu SUDtraction 01**Vt;I,;~UI:>** \ng. U'tJ 

### <11t;**U<l:>~\'; ~u**  

### Lilo; "V**u.~** r "",' 

### computations used to present and analyze flow, circula- be associated with a positive or negative concept of tion, and flushing patterns. Figure 

### 24A shows two directionality. directional-line**se~ments,** 

## A and 

## 13, that represent the magnitude (proportional to the line length) and direction Longitudinal Summary of two vector quantities, such as water or constituent



## ...**'~** 

# - _. 

# . A 

## ..**\11"~** 

### • 

### -' to lri:1US£,Ort. VCl,;lUI \ug.**~D}** 

### lCSUHS u, .....u ..... ",,,,- 

# '. IA D\ nO • 1..••**1:~~ +,p~_** **.I.~** • nn;nt nf 

### thp effect of chanl1:es indicated by the**~'V~** 'J

_ 

# . transport-change maps and to answer the following ques- A to the ending point of B. Vector subtraction (fig. 24e) also results in a third vector 

## (A
- B) defined by a line tions: (1) Has dredge-and-fill construction (channels, from the starting point of A to the ending point of - B . islands, causeways, and so forth) causea sIgmncam Model Results and Analysis 35

### N 40' 35' 

### 30'



# + Sampling site per liter

- - - - Ship channel

--- Line of equal concentration

5 

## , MILES

36 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaA Item 4 is computed by summing all residual, constituentVA"'"'' h".h

_ <Inri ll11lfward-flowinl1 normal to a cross section. Item 5 is self- V

# y Vector explanatory. 

### B 

### Water Transoort 

# / Water transport is computed at water-depth locations of the finite-difference scheme (fig. 5) by using the cell 8 

### B dimension (l,500 ft), the depth value, and the four velocil.y anu lour Water-lt:Vt:l Vl:llues on Lne siut:s i:lIlU ofthe surrounding square. Transport, rather than velocitv W"'i: rhn"
..n "" th
.. nnit tn f1nw and**cir~nl,,-** tion results in this study to avoid potentially misleading Vector addition 

### (A +

### Bl visual portrayals. The length of a transport vector is directly related to the quantity of water being moved, 

## c wnereas large velUdlY vt:cwrs can oe WllIl llLue 

### -13 water transport. 4 

# / nuuu dnu I:DD
.......el


# . . .... A· tl 

# V A 1 YPl\;i:ll Wi:llt:l- .C • ""u"'5 'Vl 1880, 1972, and 1985 levels of development are shown in filmres 27 28 and 29 resnectivelv. The transoortVector S4JbtrKtion

### (A 

## B) vector maps show many similarities, including flow concentrations at the mouth ofTampa Bay and Old Tampa**Fh~ure** 24. Computations for vector addition and subtraction. Bay. Each map also confirms that regions ofhigh transA and B represent the magnitude and direction oftwo vector 

## .. 

# . ". pUlL all;; <lUl
........ }-I, .a".- -'" quantities, such as water or constituent transport. areas ofthe bay and that low transport regions are coincitipnt"l with "h"llnw areas. For areas of similar denth changes to the overall circulation and flushing character- transport magnitudes generally decrease with distance istics of the bay? and (2) How large are the changes in from the Gulf of Mexico. various parts of the bay? The magnitudes and directions of flood-transport vecThe tecnmque summanzes computea transport Hong __ • • •• • "" T • lUIS i:ll 1t.:J I>U<;I> al <; 11l>ll;;U 111 .av..... v. a series of cross sections within the bay. Each cross sec- of the sites are shown in figure 27, and reference dots tion extends from bank to bank and is approximately are given in figures 28 and 29. From 1880 to 1985 levels •.. the nredominant direction oftidal flow. ofdevelopment, vector magnitudes were computed to deThe series ofcross sections extends from the model boun- crease from about 105,000 ft3/s to 97,000 ft3/s at the dary in the Gulf of Mexico to the head of Hillsborough mouth ofTampa Bay (site 1), from 37,000 ft3 

### Is to 29,000 and Old Tampa Hays along the 10ngltUamal summary**~.** 

## . .. - 

## .**~,~ -~,"~,**  """ U-IS111 1111U-li:llllpi:l va, \I>U<; 7), 11 Ull1 ,vvv.. "'V ,vvv

•**.~.** _, • L" d. r.3/. ;,.. Al,.1

- n<l" {.;
... "'" ",,..,.1 r..**,,~** , MfI ft3 I
.. IlIlt:S I>I1V..-lllll**i1~UII;;** Jt.U. ll11UI UVU1--.rro;;- -, ,. model for each level of development for each cross sec- to 1,000 ft3/s in Hillsborough Bay (site 18). tion includes: At some sites, significant computed increases in trans1. water and constituent transport during a typical port magnitude or changes in direction among 1880, 1972, floodtide, and 1985 levels of development are evident, such as at 2. water ana constituent transpon aunng a typical eoo- •**~,** ,.**_~** -' "',..
.... .L I>lL<;1> -', U, lU, 17, ...v, au.......... Inv". "lL"", , »uv



## .. 1;..1..**;~** _;.. 1.. •• " ... , nf f1nnrl_ UUt:,**.~** 3. landward-flowing residual water transport (defined as transport vectors. tide-induced circulation for nurooses ofthis reoort) Typical water-transport patterns during ebbflow for 4. net residual constituent transport (defined as total con- 1880, 1972, and 1985 levels of development are shown stituent flushing due to tide and streamflow effects), in figures 30,31, and 32, respectively. Overall ebb-transand port patterns, although opposite in direction, are similar

, 

### " 

# .. " ._-'- tn f1nnrl_ "hnwn in fi<Yl1rp.'i: '.7 'It "nti J ••Ulal Ula"" v. .a..... a..... v.......... ·c cross section. 29. Flow concentrations occur in the same general areas, Hems 1 lInd 2 are comnuted bv summing the ao- and transport magnitudes are greatest near the mouth and propriate vector components normal to a cross section. least near the head of the bay. Item 3 is computed by summing all landward-flowing, une aurerence oelWt:t:Il BUUU anu eoo . II> l11al residual, water-transport vector components normal to maximum ebb transport is substantially greater than max- ,- 

## . 

# - . imnm f1nncl 

# . t the bav. This difference a \;IUI>I> "......LlVU. '-'w .. , .....- 

### .'" .'" Model Results and Analysis 375min 10min 15min 20min 25min 30min 

# V ,,/ 

## / ./ ---'" 

# - 

# - i=l i=2 i=3 i=4 1=5 i=6 5-minute transport vectors I vii 

# .// 

# P:/

" " " " 

# l/" "
6 11 Summation of vi 

## :( Ivi) Average-transport vector: I**~_I** 

## vi I 1=1 i=l

A. Computation for average transport vector for flood or ebb conditions.

'", 2/ 

# 1\ Il 

# , , ,

# 'X/ '\ / !s,mm'''O"Of24hO,'', transport vectorsW j I, each the summation of 12 5-minute vectors

# //~:/" 

# \ VII**Vi~~V'** / /' " / 

# "' 

# \ r--/ , 

# , j=1 

# .r Residual vector 

# , 

# II
/ 

# \

", 

# \,//
Residual vector= 

## 2; Vi 

# ------ 

# "" :/ / 1-1


# -----------

.
B. Computation for 24-hour residual-transport vector. Figure 25. Computations for average flood- or ebb-transport vector and for residual-transport vector.

38 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

# "" \



# .( 'V' A ZONE 7**~vru::** Q \

### I~" 

## /' 

# X jHi/lsborough -



## 1\

\ 

# A 

# -

\ 

# T ZONE 4 \" 

# r

TAM P A : 

### 8 A ;" I

" Boco 

## I**~f'** Ciego 5 '\]., I 

# l/ '-**~~** 

### ! _, L ) ZONE 3/" 

# j::?'./J LONGITUDINAL SUMMARY LINt:::>**""""\~** • .1, , AND DISTANCE, IN MILES ./t'A .•.



# ------



# -- 5MILES I


# \ o 1 2 3 4 I I I I I CIRCULATION ZONE BOUNDARIES AND TYPICAL CROSS SECTIONS



# - 1r'4, /**~[V** 

### o



# ---- Figure 26. Longitudinal summary lines and circulation zones of Tampa Bay.

Model Results and Analysis 39............ '" 

## . 

# .. ",

# .. , 

# .

... 

### , ........ '\ " , 

# .. .. ", .. ,.,Il, .... 

### ",,,,, '\ 

### . &"",1."" II-

... "\,,\\ .. ,,,. a","""4' •
... "\\'\,'\,'\\,,. 

# .. """"", .. ,

....

### "

### ,\ '\ '\ '\ '\ \ \ .. " -"



### ... 

### """"" 

## -

# .. """",,\, .. 

### - ...

listed in tables 10 11 13 15 16 and 18. EXPLANATION LOCATION OF MODEL COMPUTATION SITE (NODEI

OF NODES TO AID VISUAL CLARITY '- TRANSPORT VECTOR WITH NODE LOCATION SYMBOL

LENGTH OF LINE 

### o 10' u...J...J...J.. CUBIC FEET PER SECOND VECTOR DIRECTION DEFINED FROM NODE LOCATION SYMBOL TO END OF LINE LOCATION SYMBOL

• LOCATIONS OF TRANSPORT SITES LISTED IN TABLE 10

40 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaINED

CUBIC FEET PER SECOND VECTOR DIRECTION DEFINED FROM NODE LOCATION SYMBOL TO END OF LINE 

### o 10'

NUMBERS) , TRANSPORT VECTOR WITHOUT NODE LOCATION SYMBOL • LOCATIOIII OF MODEL COMPUTATION SITE (NODEI SYMBOLS ARE SHOWN FOR AID VISUAL CLARITY \. TRANSPORT VECTOR WITH

5 MILES 4 

### o Figure 28. Water-transport pattern during typical floodtide in

Model Results and Analysis 41

# .. ,.,

## ..

# ,. ,

# ... .. , "''' " , , , , 

# . , 

### . 

# .. 

# . .

... 

### '" \ " \ 

### , " " , " " 

### . """Il,",,""'.

... """,,,,,, 

## . 

# ..**"""",,,,.~.** ... """",\" 

## . 

# ..,"""'"'.' .... ... "",\\\'\\, .. - 

# ..**"\,,,\.,.,.~** ,
... ,'\'""" .... , .**-""------,~,////'.,** 

### ....**~,"'~---r'~'~/~J.'** •.•.•. ' ... ""------"",,,., .....
..........**~,.-.-r'~~~'~'** •.•.•.•.•.• -" 

### .....**------",-~~",** •......... ·".' ..**~.-r-r'~'w~.'** •••.•.•.•.•.
... ,**-----",,-~-_.,** . 

# ·1**-.·.~.~.·.·** 

# · .

42 Tidal·Flow, Circulation, and Flushing Changes in Tampa Bay, Florida EXPLANATION LOCATION OF MODEL COMPUTATION SITE (NODE) L ARE SHOWN FOR 25 PERCENT OF NODES TO AID VISUAL CLARITY TRANSPORT VECTOR WITH NODE LOCATION SYMBOL

LENGTH OF LINE 

### o 10' lli.llJ CUBIC FEET PER SECOND VECTOR DIRECTION DEFINED FROM NODE LOCATION SYMBOL TO END OF LINE LOCATION SYMBOL

• LOCATIONS OF TRANSPORT SITES LISTED IN

TABLE 10 (SEE FIG. 27 FOR SITE NUMBERS)LOCATION SYMBOL TRANSPORT VECTOR WITH NODE LOCATION SYMBOL

eve opment. SYMBOLS ARE SHOWN F R

F NODES TO AID VISUAL CLARITY

LENGTH OF LINE 

### o 10' L....w...,j CUBIC FEET PER SECOND VECTOR DIRECTION DEFINED FROM NODE LOCATION SYMBOL TO END OF LINE LOCATION OF MODEL COMPUTATION SITE (NODE)

• LOCATIONS OF TRANSPORT SITES LISTED IN TABLE l' (SEE FIG. 21 FOR SITE NUMBERSI

Figure 30. Water-transport pattern during typical ebbtide in Tampa Bay for 1880 level 0

Model Results and Analysis 4344 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida EXPLANATION LOCATION OF MODEL COMPUTATION SITE (NODEI

SYMBOLS ARE SHOWN FOR 25 PERCENT 

### l. TRANSPORT VECTOR WITH NODE LOCATION SYMBOL VECTOR MAGNITUDE DEFINED BY LENGTH OF LINE 

### o 10' CUBIC FEET PER SECOND VECTOR DIRECTION DEFINED FROM NODE LOCATION SYMBOL TO END OF LINE

ay or 1972 level of development.• LOCATIONS OF TRANSPORT 

# , EXPLANATION LOCATION OF MODEL COMPUTATION SITE (NODE)

TRANSPORT VECTOR WITH NODE LOCATION SYMBOL VECTOR MAGNITUDE DEFINED


### o 10'



### ............... VECTOR DIRECTION DEFINED FROM NODE LOCATION SYMBOL TO END OF LINE T NODE LOCATION SYMBOL (SEE FIG. 27 FOR SITE

Model Results and Analysis 45Table 10. Water transport and direction during typical floodtide at selected sites in Tampa Bay for 1880, 1972, and 1985 levels of development

Site no. (thousands of cubic feet per second) (degrees, clockwise from north) (see fig. 27) 1880 1972 1985 1880 1972 1985 

### 1



## --------------------------- 105 101 97 114 114 115 2



## --------------------------- 71 68 67 69 69 70 3



## --------------------------- 36 33 33 65 65 65 , 

# -- -- -- ---- -- --- ---- -- 

# ... "'0 "'0 

# .."

.. 0 '+/ 

### 5



## --------------------------- 58 63 65 51 48 48 6



## --------------------------- 14 11 12 45 85 85



# -**,~** 

### -- ---- - 

### ----- --- - --- 

# ..... "'
...... 

# .... "J 4.l 

### 8



## --------------------------- 25 24 25 31 32 31 9
- --- - ---- 

# -- --- -- 

### 37 35 29 28 28 32 10



## --------------------------- 22 21 22 29 30 31 11 '1 ')Il ,)Il '20 '211 "0 

### -- 

### 12
- -- -- -- --- --- - - 

### 15 14 13 

### 16 14 15 13



## --------------------------- 20 21 23 19 17 15 14



## --------------------------- 6 5 5 59 59 59 1.0: 1.0: 

# .'" 

# . "'.,**~~ ~~**  

### ---- 

# -- ------- -- 

# -- -'-' 

### 16



## --------------------------- 10 17 16 24 39 54 17



## --------------------------- 6 6 4 6 31 355 , 0 "l 

# . ""

# .. "

" 

# -.-
--- 

### --- -- ---- -- -- 

# . JJ J"V 

## "

# .." 19



## --------------------------- 4 1 2 348 348 31 20



## --------------------------- 26 31 30 359 356 356**~.** n , , 

# -**,~** 

# ... - -- - - --- -- -- - v V V ""0 

## ""**"'~/** 

### 22



## --------------------------- 14 19 19 313 316 316 23
--- 

### ----- -- 

### ------ 7 

### 10 10 

### 298 285 285 24



## --------------------------- 2 4 4 251 280 280 25



## --------------------------- 7 4 4 305 348 348
is caused by the faster rate ofwater-level change for faH- in most other areas, particularly where natural or man- :

__ ..:..:1_
.. 1.

__**~~. _:~:_**  .. :..:1 ..:I • ..:_ .. 1 • •. U'! -_..:I _L .1

"CO "0 ._- - ... "'0 ... - \He;. ........._ " .. v ... " v

__..... ", Th,. f!:ld,.r r!:lt,. i,," h" !:I .•; ..... '"**n~** ",1..1.._ flow duration. Ebb-transport magnitudes and directions Flood and Ebb Water-Transport Differences for 25 selected sites are given in table 11. From 1880 to For 1880, 1972, and 1985**19~5** levels of development, ebb-transport magnitudes Figure 33 shows computed flood water-transport difwere computed to decrease from 239,000 ft 3/s to about ferences for Tampa Bay between 1880 and 1972. Com- ""'2 f\IV\
.. 3**/~** n" .. I..", 

# .. n 

### .w. ,_, 

# ., .... ,**,~-~** 

# . -- , 

# .... -, \"

# ......., 

# .......**}JU.~'"** 17' ... CUI". J "0.1 i:tn::: snuwn HI from 51 000 ft 3/s to 40000 ft3/s in mid-T!:Imn!:l R!:IV (<:it,.**~:~** ...'" '2/1
- .<'1, ..:I

_ .L -." ....... " .. v ... 9). Ebb-transport magnitudes increased from 8,000 ft 3/s in both figures, with more and larger changes indicated to 13,000 ft 3/s in Old Tampa Bay (site 23) and remained between 1880 and 1972 than between 1972 and 1985. The constant at 3,UUU 1t"/s m HIllSborough Hay (SIte 18). largest changes are the result of (1) shoreline changes in The most visible differences between flood- and ebb- Boca Ciega and Hillsborough Bays (fig. 1), (2) constructransport patterns occur in localized areas that are alter- tion of causeways for four major roadways, (3) ship- n!:lt,.h tn !:Inti th,.n •• • frnm .;..1.,1 . .,nrl IA\**.;..~-** due to the presence of islands, causeways, shoals, or islands and submerged disposal areas. Channel and island points ofland. A good example is near the eastern shore construction between 1972 and 1985 has and will cause of Egmont Key, at the mouth of Tampa Bay (fig. 1), additional changes in Hillsborough Bay and along the



# - . wnere 'IUW -c i**~see** smp cnannel rrom mIQ-l ampa J::Say to tne Gull ofMeXIco. fig. 29) and ebbflows produce high transport magnitudes Areas totaling about 218 mP sustained flood-transport {",.,. fia 

# ':I." Thp . • pffl"rt i" rn .t'h rnnr.. .,11ht1
.. 

# . nf th!:ln 1 fl 1 QQIl n_rl

.... .... c 46 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

# .Kj(**':::::::::::::::::::~~:** 

# ... "'I ••••••••••••• :.**~~**
...... .......................... It .. .. , ..

.. ) •••••••••• 1I ••• 1IC1IC

.. :.: =-=--It ::: : : : : : : : : : : : : : : I .. :::::::: 

### I: ::;: ,

.... ............ x. I 1' •••• 0_



## ..**~~··:::** 

## ..**~:::::::·l·** ,- .liC········ ;;

................... .. leJelt.

....... .. .. .. .. :I
.. lit
.. .. .. .... .. .. .. 1(. It Ie


### .... ..**:~~~~~~.** :.. 

# 1\ 

# -- .. :::::.:""",

# ~~ :: 

### : ::**.~** 

### :

# . . 

# .

.. '..I 

# X······Z ,- 

# ..**::::~::** 

## ::: 

## :::::::::::

.. .. .. .. .. .. .. .... ::::::::::::: :;':fj 

## -....:. ::'. I.. . JI.I 

# J**,, ~::.**  

# .::: :::::::::.::.. .... ... :'. ::::::::::....::....:::.:.:. r ) :::::'.**~::** 

# ::: r

# -~¥'"**~.:** ... 

# +il: l'

## ::~~::~~~~~~:It\_ ..**--~-~"** 

## ..... .......... ···e

.......................**~.A!a..** 

### ::::**;;~;:: :.;;~~**  .:::::: ••• "r", " "."**~::::;:**

# ..**~~** 

# .::::**:~::::~~~V"r** 

### J SYMBOLS



### • x 

# o 

# • EXPLANATION PERCENTAGE CHANGE 0-10 11-50 51-100 101 200

>200

# :::S\::~1~ ::::: .. • : : : : ; : .. 0 1 2 3 4 5 MILES

..... I I 

# \ rlgure .u. Lnanges in warer uansporl i dllllJd DdY lUI l yt_" '-0 I

Model Results and Analysis 47\.\),**~'l."'3** 

## •

0-10 1-00 51-100 101 200 PERCENTAGE CHANGE EXPLANATION \



### x 

# . u SYMBOLS 

# .ffJ 

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.. 

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... : \I ... _a_ r • •• • •••• ·_CD

.. . .•••• e - 

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••• II ••**~~** •••• " , , , 

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### . .

48 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaTable 11. Water transport and direction during typical ebbtide at selected sites in Tampa Bay for 1880, 1972, and 1985 levels or oevelopmem

Site no. Transport Direction (see fig. 27) (thousands of cubic feet per second) (degrees, clockwise from north) n, 

# ---**.nn~ ,n..,~** **n,,~** 'uuv "'"

# .. 1



## --------------------------- 239 232 223 290 290 290 2



## --------------------------- 116 112 113 243 243 244 ':I '7**,~** 

# ,'" ,,,n 250 250



### - ---- - ---- 

### -- 4



## --------------------------- 40 45 45 224 224 224 5



## --------------------------- 89 90 104 231 230 232

It. .,n "1 

# ,., .,.,0 

# ,"''''**,~~** 

### - -- 

### ------ 

# -- 7



## --------------------------- 66 

### 60 39 225 224 224 8



### --------------------------- 40 38 40 

### 206 206 206

- - ---**~1 4~**  ,+v ,,:,vo ..:.V .<.,! 

### 10



## --------------------------- 29 29 31 213 216 216 11



## --------------------------- 31 28 27 216 215 215 12
-- ---- - --- -- - 2U 

### 19 HS LUj LU4 ..:.v,+ 

### 13



## --------------------------- 24 26 27 207 205 203 14 

### 10 9 9 246 246 246 15



### --------------------------- 20 26 24 234 228 226 16



### --------------------------- 14 18 6 201 215 245 17 R Q 

### 6 187 214 198 18



## --------------------------- 3 3 3 166 167 170 19



## --------------------------- 5 2 2 172 169 182 LU ,_n -"

## ..
- -- - 

### - -- ":'1 --yr JU ! 'J ! " • J 

### 21



## --------------------------- 8 6 6 164 143 143 22



## --------------------------- 12 17 

### 17 137 143 143 L3 

### -- - ---- - --- - II !'t {J T.<..<. !VV !VV 

### 24



## --------------------------- 2 5 5 

### 88 135 135 25



## --------------------------- 7 5 5 129 150 150


### 1972. Areas totaling about 53 mil will sustain similar ways, and shoreline fills. Areas totaling about 188 mP changes between 1972 and 1985. The following table gives sustaIned ebb-transport cnanges or greater man 1U 

### pera breal«fown ot percentage cnanges ana size or arreCLe{[ __ ,n__ • " " I,;Cl1l**~ClUU J"7/~.** **~CCl;)** -0 avvuc .v .... 

### areas. The computation ofpercentage change at each cell will sustain similar changes between 1972 and 1985.**:~** 

# .**~.** _ ••1." nf 10**Pl"rcenta~e chan~es**  

### and size of areas involved are given in the following table: Water transport, floodtide Percentage Area of change, in square miles Water transport, eootloe

change 1880 to 1972 1972 to 1985 Percentage Area ot Change, In square miles 

### 0-10


# ------ 244 393 change 1880 to 1972 1972 to 1985 

# .- .,n <1\ 

## ..... ! !'-JV

______ .vv <"" V-IV

_____ 

# .. 51-100



### ----- 51 8 11-50

______ 130 38 101-200

----- 

### 6 1 51-100 53 7



### ----- >200
--- I 

### 0 101-200 5 1

- - 

### " ":'lJ\J 

### - - 

### Figure 35 shows computed ebb water-transport differ- 1 00"**n~,.l** 1 n.." £"" 

# . h",. 

### Fil!ure 37 shows tvnical floodflow and ebbflow deter- "'""'''',, v",c ._.. _ • tUlPpn 107' l:md 

### 1QR'i lIre shown in figure 36. Areas of mined for each cross section along longitudinal summary ebb-transport change are substantial and similar to those lines (see fig. 26) for 1880, 1972, and 1985 levels ot computed for flood transport (see figs. 33 and 34). The development. Progressive flow reduction throughout the largest changes are closest to channels, ISlanas, cause- 

### ,. 

# - --- UClY UVCl UIUC 1;) Cl V! u'J 

# .... "'" Model Results and Analysis 49

### I: -1:.".'**.~** ....,L 

### l.. 

# J
1.'00 

# j: ::::::::::::D**~_~** "'llll1 • ••••••••••••• Q**DDD~**

... .. a**~tj·u·~·~·Li·o;·~ ·~lC~iIQ~~c--------~,A-!-~ll-~~f1f------------------------1--** 

# ~~**.;:~::u gg::::~::::::::.~::.**  

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## •...•........... .,

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# r; III III...... .. .. .. .. .. •••••••• • •••• '. ". " ••••••••••• ",," •••

.. • III .

.. .. .. , _CCa" , , , .. .. .. 

### .... .. .. .. .. .. .. " .. .. 

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# ...;i:."" "".. 111 .. .. .. .. .. ;: ..



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### = .. •.. .. .. .. .. .. .. .. .. .. .. if 

# . . ,,,**:::::::::::~.::**

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\ EXPLANATION SYMBOLS PERCENTAGE CHANGE 0-10
51-100 101-200

>200 11-50 x 

# • o 

# •**::::~::~** ......... 

# ....... 

# .......


# ::::::::=.......=:r11 /' J V 

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## ...

# :::::~·~o 3 4 5 MILES 

# \ rlgure ,);,. Lnanges In water transport in Tampa Bay for typical ebbtide between 1880 and 1972 levels of development.

50 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaA,fa:

# '.~. .:·l," )J,,_

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'1

51-100

0--10**.~'** 

## ---

11-50 101-200

>200 

### PERCENTAGE CHANGE**~~,~.** ,IIUN



## • x 

# o 

# • SYMBOLS

### '" • !-- • ::

### ':::.=:~~ 

# . ......... 

# ... 

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. 

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### .... 

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### .. 

## .....**~l** 

# /J V

# ~~'--'------------+-----1**~~** 

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# 'V
..\ 0 1 2 3 4 5 MILES 

# \ Figure 36. Changes in water transport in Tampa Bay for typical ebbtide between 1972 and 1985 levels of development.

Model Results and Analysis 511.4 

## t"\.

# ~,"" IU.;jU III.. 1.3

# '~>~**~B** , ' 1880

### I~'~, 0.'Z5



# "', 1.2

# ~'~ ------- 1972

# '~~~ , ,',**~:!lo. ~~l'iI**  

# ""',

---- 1985

## '~~+. 0.20 

## '''-.' 0 1.1

... 

# '" FLOOD

### '~~~ 0

, 0.15 

## 0

## '~~ U "**'~** U w 

## \, , w (J) 1.0 

### " (J) II:

### '\.~<:'\.EBB 0.10 

## ffi , "'-

# ~\~ 

# '\ 0.9**~,** w , w w 

## ''':, UJ LL 0.05 LL U

# ,,:~ u iii 0.8

....

# "

.... iii :::) 

# --- :::) U**,~,** U 

# .. LL**-_::::~"-** 

# ''''0-. 0 5 10 LL 0**~-** 

# -'-::,----**DI~TAN~1t** ItROU 01 n TAU"A .,AV 0 (J) 

# -:--**~'~** ENTRANCE, IN MILES (J) Z**-....::::~,** FLOOD ' , Z 0**"~""'":..."''''** 

# "'

... 0 ::::i , 

### , ::::i v ...

# ""-~~~ .;jU
..... 

# --, "\:, Z**:~ ~,** **~~...... "~**  ... 0.5**.~,** 

# "4 \ •**0.25~·** II:**"~** ... 

### :-r lr

### ~'~

## ~EBB 0**~,** Q.. (J)**.~-** (J) Z 0.4 

### " 0.20 

### < 

### '::..

# .. ,

## ~\~~ II: to- 

# -

# ~~~ II: UJ 0.3 • 0.15

# \.~, 

# "'\" < 1: 1: 0.2 ' 

### ": 0.10**~"** 

### \'

... FLOOD

### '~,**"~"** ",**~\~~** In no:: 0.1 "":,,> ...

### ~~~**~-**

n 

# . -

0 5 10 15 20 25 30 35 40**-ursTANCF~** MODEL BOUNDARY IN GULF OF MEXICO, IN MILES Figure 37. Water transport along longitudinal summary lines (see fig. 26) during typical floodtide and ebbtide in TamDa Bav tor HmU, 1YlL, and 1**Yl:l~** Tevefs of development. 

### and tidal prISm (see table 2). Water-transport and per- cause minor flow reductions into and out ofOld Tampa**.~ ~OI**  

### are given "Hay. in table 12 for the seaward end ofeach major bay subarea (see fig 4). A of t<lhlp , <Inri t<lhlp l' "how.;: Residual Water Transport 

### that the greatest changes in water transport occur between Figures 38,39, and 40, show computed residual waterthe times and in the areas that have the greatest change transport (circulation) patterns for 1880,1972, and 1985 in surface area and tidal prism. levels of development, respectively. Each vector map 

# .. 

# . Shows a senes ot 

## :w or more CirCUlatory t"eatures or gyres JUli111 -r III Wi:Ut;r**~li:lUlt;** 

### 12) for Old Tampa Bay between 1972 and 1985 were that range in diameter from about 1 to 6 mi. These 

# . no wPrP 

## .. 

# .

- r1ohno**.:-1~"** • ""t..... .**~~.** _:"0-1 

### in that part of Tampa Bay. Apparentlv. a change in the tide in the absence of density s 

# .-. <Inri winrl 

### distribution oftidal flow between Hillsborough and Old effects. Tampa Bays, as a result ofchannel constructionbetween Residual transport-vector magnitudes are several times**.~-~ .~,.,~**  

# ... . 

# - --.... -**171~i1UU** 170-', WU1",uO' &J Ii:lVUI -0 Di:lY ClUU 

### greater near me emrance LO 1 

### ampa ooy man at most IOca52 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaTable 12. Flood and ebb water transport and percentage changes in Tampa Bay for 1880, 1972, and 1985 levels of development

u _l Area (cubic feet per second) 1880 1972 1880 1880 1972 1985 to to to**I~/L I~O:>**  ':10:> During typical floodtide, computed at the seaward end Lower Tampa Bay

_____________ 7.46 x 105 7.09x 105 7.00x 105 -5.0 -1.3

- 6.2 

### ""''''.n T. n 

# .... II\<**,~** 

# .", "" ,", 

# .. 

# .. 0 ._......- -'J - ---- --- 

# ...**.~** • T.**.~** ••J 

# . 

# ...**.~** Old Tampa Bay

______________ 2.43 x 105 2.32 X 105 2.30x 105 -4.5
- .9

- 5.3 Hillsborough Bay

______________ 0.91 x WS 0.83 X 105 0.77 x 105 -8.8 -7.2 -15.4 During typical ebbtide, computed at the seaward end Lower Tampa Bay

_____________ 11.94 x 105 11.55 x 105 11.35 x 105 -3.3 -1.7
- 4.9 Middle Tampa Bay

____________ 7.94 x 105 7.66X 105 7.53 x 105 -3.5 -1.7
- 5.2 Old Tampa Bay

_______________ 2.78 x 105 2.62 X 105 2.60 X 105 -5.8 - .8
- 6.5 Hillsborough Bay

______________ 1.28 x 105 1.18 X 105 1.10 x 105 -7.8 -6.8 -14.1 tions within the bay. At the scale of figures 38-40, cir- other and to partially or wholly cancel residual transport culation patterns near the entrance are not easily dis- where the pairs join. cernea. J:mtrance ClfcUlatlOn patterns ror HSlSU, I':J /L., ana ill spire 01 me large lOcal variaoiIitY in compULeU 1985 levels of development are very similar because few residual water transport, the overall pattern of circulaphysical changes have been made in that area; figure 41 tion for each ofthe three levels ofdevelopment is similar. shows a reoresentative residual oattern at an enlarged Maior gvres that existed in 1880 can be identified in the scale. 1972 and 1985 maps. Detectable changes include deflecComputed residual water-transport magnitudes and tion or skewing of gyres, strengthening or weakening of OlreCtlOns are given In table I j tor L., selectea sites {see resiauaHransporr vecTors, alKf aaarnon 01 new gyres £'.' .... £'.' • ...... • L' • • . . ••.:.1.. . ...I.**...~A** ue..... .v. ••'" 

### '''''e''' uv,,, 

### , , 19,300 ft3/s in 1880 to 18,100 ft 3/s in 1985 at the entrance channels. to Tamoa Bav (site 

## n. from 1 200 ft 3/s in 1972 to 700 Sufficient tidal current data have been collected by the ft 3Is in 1985 at site 9 in mid-Tampa Bay, from 400 ft 3Is NOS at two sites in Tampa Bay, Ross Island and Egmont in 1880 to 1,200 ft 3/s in 1972 at site 23 in Old Tampa Channel (sites 25 and 26, fig. 8 and table 7), to deterBay, and from 400 ft 3/s in 1880 to 500 ft 3/s in 1985 at mine long-term residual currents for comparison with n' TT' 

# . 

# . ." .J .1 _1. ....,. •••• •• L'. 11 •**~H"** ." 'I! . .L>ay.oy**~au** ..." • v, ", •nvu", ••**"'~u** ..**~. ...,...,...~**  

# ...... and 13, the degree of residual-vector variability among table: levels ofdevelooment can be seen to be much greater than the corresponding variability in either flood or ebb vec- Residual current tors for many sites. The sensitivity ofresidual transport Location Measurements Model to physical changes in the bay is greater than the sensitivi- Ross .r L'1 _1..L .1- 

# . .J v, uvv" v. "'vv .v ...'"**~u.n",** IslanCl

__V.JL. I1IS lL.. K. MUir- V.u::>'**1l/~** en

Circulation at the entrance to Tampa Bay 

### is dominated head, written commun., 306° clockwise bv (l) large gulfward-flowing vectors in the deeD chan- 1983) in flood direction from north. nel north of Egmont Key (site 1, fig. 41 and table 13), (358°) (from Dmardl, ;"
.. n .. " (2) small bayward-flowing vectors at other locations at • 'v,}o. the entrance (sites 2 and 3, fig. 41 and table 13), (3) in- Egmont .11 ... 

### " • r.

__ 'I:l Channel _0.29 fUs in ebb direc- 0.27 fUs at w .. ... , cJ
....**~p'V** .....**~~J ,~**  .. uv .. ·**~c** tion (289°) (from 284° clockwise mont Key, and (4) significant south-to-north residual Dinardi, 1978, p. 30). from north. transport about 1-2 rni bayward of the entrance. Gyres and residual-transport features near the entrance to Tampa Bay adJOIn other less Intense gyres Within the At Egmont Channel, the comparison IS very gooa.Ine bay (see figs. 38-41). Each gyre or residual-transport residual current speeds determined by both measurements



## .. • 1- " .J .1 .J.1 • ..:.1:_ 1(\**~-...I·,I** 1'''''. v ....... ... p' -0" 

# " ........".V u ..u ...... ...v...... u. '" ....., , th" h"",rI (\f TT' "'nrl ()lrI
....**R",,,~ ~nTt1"**  ,."nt .... . mhh;n "1 0 At th"**Rn~"** Island site 

# . gyres mesh like a pair ofinterlocking gears and enhance the comparison is not as good as at Egmont Channel but residual-transport magnitudes where they join. Other is sufficient to indicate a fair level ofagreement between pairs ofgyres seem to rotate m drrectlOns opposite to each measurements and model values, partIcularlY In a regIOn Model Results and Analysis 53I, I I, {'

I' \/'

...' 

# " " 

# .I' 

### a 3 4 EXPLANATION LOCATION OF MODEL COMPUTATION SITE (NODEI SYMBOLS ARE SHOWN F R 25 PERCENT OF NODES TO AID VISUAL CLARITY NODE LOCATION SYMBOL VECTOR MAGNITUDE DEFINED BY LENGTH OF LINE
CUBIC FEET PER SECOND VECTOR DIRECTION DEFINED FROM NODE LOCATION

, TRANSPORT VECTOR WITHOUT NODE LOCATION SYMBOL

• LOCATIONS OF TRANSPORT ISEE FIG 27 FOR SITE NUMBERS I

5 MILES Figure 38. Residual water-transport pattern in Tampa Bay for 1880 level of development.

54 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

### o 3 4 5 MILES
Fi ure 39. Residual water-transport pattern in Tampa Bay for 1972 level of development.

Model Results and Analysis 55

### o 3 4 EXPLANATION LOCATION OF MODEL COMPUTATION SITE (NODEI SYMBOLS ARE SHOWN FOR 25 PERCENT OF NODES TO AID VIS AL NODE LOCATION SYMBOL VECTOR MAGNITUDE DEFINED BY LENGTH OF LINE 

### o 5000 CUBIC FEET PER SECOND VECTOR DIRECTION DEFINED FROM NODE LOCATION SYMBOL TO END OF LINE

" TRANSPORT VECTOR WITHOUT NODE LOCATION SYMBOL

• LOCATIONS OF TRANSPORT SITES LISTED IN TABLE 13 {SEE FIG 27 FOR SITE

5 MILES
Figure 40. Residual water-transport pattern in Tampa Bay for 1985 level of development.

56 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

# ~.~.**:~iJ~·~·** 

# .: r· :. . .
- ... . - . ..**~<-** 

# , \ EXPLANAnON
• LOCATION OF MODEL COMPUTATION SITE INODE) SYMBOLS ARE SHOWN FOR 25 PERCENT OF NODES TO AID VISUAL CLARITY '- TRANSPORT VECTOR WITH NODE SYMBOL LOCATION ,,,:('Tn,, UAr-lU'T"n<: ""<:'....<:n BY LENGTH OF LINE o 20000

### ::::::::::~~ 

# ...**~--** 

# :,

, , - .. , .. , .. , .**I~** 

## ,. . .. \
.. : : = : = : : : : :, \

# l\~ i ' 

## 't :. . • .\. "

....... , ...... 

# ", \ CUBIC FEET PER SECOND VECTOR UIHt:C IIUN DEFINED**~HUM** NUUt: LOCATION SYMBOL TO END OF LINE "TRANSPORT VECTOR WITHOUT NODE LlJ(;A' IVN SYMBOL
• LOCATIONS OF TRANSPORT SITES LISTED IN TABLE 13 "\ ... 

# . ... 

### , , ... .. .. \ , I I



## " " ' , , \ \ \ \' '1_ t\... V· - , . - ". 4' •**~\I\"'~\\\"~** ""1 .•. 1', •.•.•

_ ...... ,. \ , ' , , \ \ \ \ \ , I , ' 

# -f . . , / , I 1 / - \
, "
.. , .. , , , ... , r ' •

### .~ . • 

## \1 \. •**~.** 

## .,' / f '
.. 

# :5

... " " " " " " " , " , " " " \ I \ /..--

__ \: --. ... / - • 1 ,-

- "' " \ \ \ " " " " " "\ 1\ \ \

## \~~--, 

# II',
. I I I ' -

.. " , I , , , , ,l '\' 

## 'f

## IlI'I '. , / I ,

I, ( .:: " "
...Key -

_ ... 1 " \ 

### 1/1 I I

"\\\\,_
.... ,,, ....... II' 

## """"'1**r'"'~'''**

'111 / "1/1/- ,\, II 

### 't ---- 

# ." ,'-, 

## .... • • • I , I

, / , 1 , I 1 1 

# . .

.. - , 1 , I I I 

# , / / / 

# , / I I I I , .... 

# , , 

# . -

# ---

... --r'/r--...--'"' ..... -_- ... 

# - 

# .. o 1 MILES 2 I

Figure 41. Representative residual water-transport pattern at the entrance to Tampa Bay for 1972 level of development.

Model Results and Analysis 57Table 13. Residual water transport and direction at selected sites in Tampa Bay for 1880, 1972, and 1985 levels ofdevelopment**c:.~ _~**  Transport Direction \"'uUJa"UJ u,**~uu,~ ,~~,** **t"'~, J~~U"UI** **'U~o'~~J,** 'U' ,un", (see fig. 27) 1880 1972 1985 1880 1972 1985 1



## --------------------------- lY.j HI.J JO.J '"'OJ '"'0'+ 2.02. 2



## --------------------------- 4.2 4.2 3.6 119 118 130 3



## --------------------------- 5.1 5.0 4.7 59 59 59 4



## --------------------------- 1.3 1.0 1.0 207 195 193 5



## --------------------------- .Il 1.4 2.4 j,j JUY 291 (\


### - .3 1.6 1.6 319 267 267 7



## --------------------------- 1.3 1.4 1.6 224 260 227 8



## --------------------------- 2.1 2.0 1.9 17b 174 174 9



## --------------------------- 1.1 1.2 .7 67 59 212 10 _'i LO .9 310 290 211Q 11



## --------------------------- 1.5 1.5 1.4 199 208 206
,**,~,** 

# - I
.. 

### -------- ------- 

### - .U .U .-' v·v 

### ...·.v ",JU 1'2 1 1 1 r. 1 r. 14'\ 1'\r. Ll


### - 14



## --------------------------- .8 .8 .8 263 260 259 15



## --------------------------- 1.2 1.2 1.3 148 166 167 16
--------------------------- .3 3.5 7.1 76 58 58 17


## --------------------------- .1 .3 1.0 12 222 283 18



## --------------------------- .4 .4 .5 187 171 175 lY


## --------------------------- . J .j .0 ,",YU JJL; IY 20



## --------------------------- .9 1.5 1.4 67 192 193 21



## --------------------------- .5 .9 .9 37 30 30 22



## --------------------------- 1.1 2.j 2.3 292 283 283 23



## --------------------------- .4 1.2 1.1 178 79 79 '4 1 1'. 1'. 210 I11Q lSlQ 25



### --------------------------- .4 .8 .8 278 87 87
of very complex, computed residual transport (see ng. more rellaOle man me reSlQUal transport values them39). selves.



# - .l' 

# .. -,**~+ +"'~~~**  .....**~:.~~ :~**  -r 

# . "",t t", ;l1t'1ap thp TTlnt'lpl'" j:lhilitv tn Residual Water-Transport Differences simulate residual currents throughout the modeled area. For 1880, 1972, and 1985 Results ofthe comparisons, although encouraging, may Areas of change in residual water transport between be SPUrIOUS for several reasons: 1880 and 1972 levels ofdevelopment are shown in figure 1. The accuracy of residual currents computed from 42. Areas of change between 1972 and 1985 levels of :"**_~+ Ir_~**  ..._ .. .'-' l': 1"1
- • _& -**~&&~** ,&& &&& -"". 

## . -.- , thp 2. Residual currents comnuted**throu~hout** the bav are frnTTl 1**SlJ~()** tn 1 Q7' j:lrp
. ",,,,,,,r'**.~** on the same order as reported standard errors be- bay, and extend into the nearshore region ofthe Gulfof tween observed and computed tidal currents (table Mexico. The largest changes are associated with causeway H); thiS simllanty InCllcates the prooaolllty or mgn construction in Old Tampa Bay; ship-channel and portpercentage errors associated with residual currents facility construction at the mouth of Old Tampa Bay; at the Egmont Channel and Ross Island sites. residential, commercial, port-facility, and ship-channel Twn**~ite~** do not adeauatelv renresent the**ran~e** of in lind ::It thf' mouth of Rj:lv' conditions within the modeled area. causeway, port-facility, and ship-channel construction in Although these shortcomings are recognized, residual lower Tampa Bay; and residential and causeway construccomputatIOns are conslaerea useIUI ana InstructIve, par- tion In Boca Clega Bay.



## . 

# . . " ., 

# ... ., ftU n::siuucu- •v,**_~** 1
.....« .. " • ....« .."
.......**v~** & " l,;Ul:tllgCS HVlll J Y 12. ro J YO;' are modification to Tampa Bay. Computed changes in due to ship.-channel construction and associated residual water and constituent transoorts orobablv are 

# . and 

# . .**~itf'~** 58 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaPERCENTAGE CHANGE EXPLANATION
0-10 

## • 11- X 51-100 

### 0 101-200 

# • >200
11"3\)'

5 MILES SYMBOLS

4 

### o 

## .... 

# ...... .

# ....

# . ......

# . ..

# .. .

# ... ........ ........



# .

# . • 1' , •• 

# ..... .... 

## ..

Figure 42. Changes in residual water transport in Tampa Bay between 1880 and 1972 levels of development.

Model Results and Analysis 59>200 0-10 11-50 51-100 PERCENTAGE CHANGE EXPLANATION



## •

5 MILES SYMBOLS

4
in Tampa Bay between 1972 and 1985 levels of development. 

### . 

## . .. 

# ...

# . .. 

# ... .. 

# . .. 

### .. .. 

### .. 

# ... ... .......... .. .. .. ..

# ...



### ... 

## ..



# ...

...... .. .. .. .. .. 

## .....

t.. . .. 

# . " ....

60 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Floridaalong the longitudinal swnmary lines (see fig. 26) for each eve 0 v . entrance. Com uted residual transport changed little in Old of Mexico to zero at the heads of Hillsborough and Old Tampa Bays for all three levels of development. Except Tampa Bay from 1972 to 1985. Although no physical changes were made in Old Tampa Bay during that period, a small difference in the distribution oftidal flow between in Hillsborough Bay, tide-induced circulation is consistently greater than the average inflow from streams. On the basis of figure 44, Tampa Bay was divided ina small change in residual transport.

Areas totalin about 306 mi2 sustained computed residual water-transport changes greater than 10 percent between 1880 and 1972. Areas tota mg a out ml sustained similar changes between 1972 and 1985. The 

### , circulation characteristics. The zones are shown in figure 26 and listed in table 14. The computed average tideinduced circulation in each zone for each level ofdevelopment so IS giVen m ta e ,Wit t e percen age mcrease or decrease between 1880 and 1972, between 1972 and and affected areas. The progression from the Gulf of Mexico to the head of Hillsborough and Old Tampa Bays consists of three sequences of high-circulation, transition, and lowPercentage

change 1880 to 1972 1972 to 1985 ClrCU atlon zones. e 1rst sequence zones , ,an defines circulation characteristics within the lower half

action between tidal water motion and bottom configuramotion in a bay. Areal changes, however, are static in nature and do not rovide information on how the

change in circulation characteristics in Tampa Bay. G es are tide-induced features that are caused b inter-



### , in the zone. Circulation throughout zone 

### 1 was greatest for 1880 conditions. Circulation was reduced by about has low circulation, about an order ofmagnitude less than zone 

### 1. Zone 2 serves as a transition between zones 

### 1 and 

### 3. 125 30 21 139 71 59 11-50

_ 51-100

_ 101-200

_

>

tion. Without the tide, there could be no mcommg residual-transport vectors. All vectors would be outgoing, dynamics ofwater motion are impacted, particularly the dynamics ofcirculatory features such as gyres. Standard methods for comparing gyre intensity do not exist. Therewould be equal to the total inflow from streams. A feature oftide-induced water trans ort is that some areas ofthe bay show residual incoming flows. To satisfy continuity, these areas are b ance y outgomg ow m ot er areas. Both conceptually and by computation, the sum
a particular cross section also equals the total freshwater stream inflow landward of the cross section.

Tide-induced circulation, as defined in the section on t e ong1tu na summary me 0 see p. , IS use as a measure of circulatory intensity. The units of tide-



## . ., 1,600 ft3/s for 1972 conditions and by another 2,800 ft3 /s for 1985 conditions. These reductions indicate that cumu a 1ve p YSlca c anges re entrance of Tampa Bay by about 10 percent. Circulation reduction in zone 1 is not considered a significant factor influencing overall flushing and constituent interchange rates of Tampa Bay. Circulation magnitudes are so high at the bay mouth, in comparison



## . 

# . . have a limiting effect. High circulation and mixing in zone 

### 1 are the likel causes for low radients of specific conductance reported by Goetz and Goodwin (1980, p. 23). Zone 2 had an average C1rcu atlon 0 a out s for 1880 level of development. Zone 2 is characterized



## . . Model Results and Analysis 6170 

### I I I 14 I 

# - Q'"

# kf('7\ 1 I 

## I i 

# , ,**~"r** ........ 50 . 

# .\**~\~** ! I I 12 

### " 

### I 

# I I ,I I 40 

# I " 

## I I II

### \~ 

# \·\1 

# I I I 30 

## I 10 I' 

## I ' 

# . .**,~** I I 

## , 1 ' z 20 

# I 

# I I : 

# , 0 

# , I 

# I , ft I 

## , I , ::; 

# I 

# J I ::>0 18 U z I I 

## , 1972 AND 1985 a:,n .' r I I UU , 

### I uuu I I:l 

# "I (\! 

# :**~w** I III 1\ 

### .. 

# a: VI I I:l '. 

## :/': - 

# -- 1 l:I ( <! J 

# 'j'V' I 1 I 

# :: 

# I !
....., \1 

# ' 

# . Oa: 

# , , 

# I . 

### " 1985 I <4 

# , I Q.w i',: ............ r rnQ. 

## ., : 

## , \I 

# , \**z~** 14 I 

### .. 

# il,: I 

# V !\( \ I ' 

### . I, 

# . <W CIRCULATION 

## I \./ 

# . a:w 

# if I: I \ t: .**~u.** I 

### : : I •. '. I 

# ---- ZONE • 2 I**~\** to:. 

### iii::::: 

### I ' ,: I**I~** : 

### I 7 

# : 8,\" 1 2 

## '
. l'A,**~111** 

# . ' Ii: • <0**II~I:** 

## 1: 1 

## I r !: I I;**l~** 00

u. • I**~:** r I 5 10 ;;'0 

### I r.**.~** TIDE-INDUCEDI II I 1n 

### , ::>rn I

## ~\ 

# /**CIRCULATlON!l~** .'0 ""

# .. o:-.v .... VL.LI I'\M'I'\ DI'\ 

# . , 

# '. ENTRANCE, IN MILES 00 

# I 1\ :. -z : : rn< I. " 

# I I\; : 

# . ,: .: , I: , 

### .. w rn I 

# V .; :: , 1 

# \.'''1' ' : I a:::> 8 

# I I::. 

## i,,: 

## I f 

### }.I 

## f I 

## I 00 

## , i..;', 

# ! "**u~** 

## , I 

# I H": : ,,:':**i"~** 1 \ .•; I I 

## I 

# I POSITION OF ::>z**~:** :' : i f I:
. : ' f .' I I . ALAFIA RIVER MOUTH IN: 0_ 6 ::' I \ 

### ;! j \ ;:\ : 

## , Z 

## , : 

## ,**~\,'.AI**

### "f(~''f/' 

# ,**;"~**

# .. .--1880 w I \('.: I



## - 

# I I 

# -0/ V·'**IVi~** i/ 

# :' I -1972 AND 1985 4 \. 

## I ;, : I I 

# I ,:......**~\** :1 . I I. I 

## I : " i', I :' 1 I 

### 2 

# , 3 

# ! 4 

# I 5

## ~!rl;~:\ 4 

### 6 , 2 I I '. h 

# I
....... 

# t'1v\ I
" AvdRAGE 

## I I 

## . 1 

# I: !\ ", , \ I TRIBUTARY STRE"rFLOW 

## , 

# i**'I;';'~""\** 

## \ 1 , r I I I J1 "Y '"-' 0 5 10 15 20 25 30 35 40 DISTANCE FROM MODEL BOUNDARY IN GULF. OF MEXICO, IN MILES Figure 44. Average tributary streamflow and tide-induced circulation in Tampa Bay along longitudinal summary lines (see fig,

... r nn"**~u,** IVI 'VVV, 1071.<0, <1IIU I**O7O~** It:Vt:I:> VI ''''

# ... laOle 

# .'t. f"\verage tlae-maucea CircUlation and percentage changes tor each circulation zone in Tampa Bay for 1880, 1972, and 1985 levels of development Distance along urCUIalion longitudinal**.~.u,,~ ~'~~".u,,~**  '""0"5" zone (see summary line (cubic feet per second) 1880 1972 1880

fig. 26) (miles) 1880 1972 1985 to to to \,t:t: "5' -<UI 1':J7L 1985 1985 1



## ----------- oto 6.5 45,500 43,900 41,100
- 3.5
- 6.4 - 9.7 2



## ----------- 6.5 to 11.5 10,400 11,800 13,400 

### + 13.5 

### + 13.6 

### + 28.8 3



### --- - 

# -- 11.5 to 21.5 4,900 5200 6300 + 6.1 +21 , ... 'R (, 4



## ----------- 21.5 to 25.5 8,600 7,900 7,800 

### - 8.1

- 1.3 - 9.3 5



## ----------- 25.5 to 31.5 2,700 3,600 3,700 

### + 33.3 

### + 2.8 

### + 37.0 {;, ':11 C**.~** ':10 l\ 

### ''''' 

### .,""**.~ ~~**  

### - 

### ----- ',JUU ... ,,,,,,,, -""oJ . 'oJ.**T~I:J** 7 1 

### oto 7.0 4800 <;.<;00 'i'iM 1<1. (, (\ 1 A t;. 

### - -- 8 1



## ---------- 7.0 to 14.0 1,400 2,500 2,500 

### + 78.6 0 

### + 78.6

,ro. 

## ....**~.-** ._•••J-- -J' 62 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

### Zone 5, leading into Hillsborough Bay, was characteriz i volume of water in the zone. Average circulation o t zone 2 was least for 1880 level of develo

- ment, with an increase ofabout 1,400 ft3/s 

### for 1972 conditions and another increase of 1,600 ft3/s 

### for 1985 conditions. Physical changes in and near zone 2 caused an culation from 1880 to 1985. Zone 3 is a 10-mi-Io re ion of low circulation between regions of high circulation. In 1880, zone 3 had an average circulation of about 4,900 ft 3

### Is, about a ofthe average circulation in adjacent zones 2 and 4 (table 6. The increase in circulation (see mi 30, fig. 44) in 1972 and 1985 was caused by the combination ofpowerplant cooling-water flow, dredging ofchannels, and construction of spoil islands at the mouth of Hillsborough Bay. Average circulation in 1880 was computed to be about 3 9 3 _c ..._>

__ 

### tidally interchanged each day, or about 1 percent ofthe total water volume in zone 5. Largely as a result of the powerplant cooling-water discharge and channe constructlOn, e average clrcu a Ion in 3,600 ft3/s 

### in 1972 and about 3,700 ft3/s 

### in 1985, a

cooling-water discharge (see mi 36, fig. 44) and extensive dredging and filling throughout the zone caused an increase in average circulation ofabout 900 ft3

### Is by 1972 o tel s oroug Iver, change each day was about 0.035 

### x 109 

### ft 3 , 

### or only 0.4 I 

### nt Zone 6 at the head of Hillsborough Bay has the least circulation ofany zone in TampaBay. Circulation in 1880 averaged about 400 ft3

### /s, less than the average ISC arge zone 3 was very low, only about 3,000 ft3

### Is (see mi 14.2, fi
. 44 about double the tributar streamflow at that water was tidally interchanged in zone 3 eac ay, or about 1 percent of the volume of water in the zone. constriction to the interchange ofwater and constituents between adjacent zones. Limited circulation is the likely cause ofthe steep specific-conductance gradients reported point. In 1880, an average of about 0.42 

### x 109 

### ft3 

### of

conditions. The circulation increase at mi 3 (fig. 44) is attributed to cooling-water discharge from a powerplant. Ion zone e ween ig r average circulation. Because physical changes are not expected in Old Tampa Bay between 1972 and 1985, one line is used in fi ure 44 to re resent both 1972 and 1985 circulation of any zone in Tampa Bay. Zone 7, the lower half ofOld Tampa Bay, is a transihowever zone 6 has and will continue to have the poorest an anot er s Increase y . cumulative circulation increase of275 percent, the largest urred creased circulation by about 30 percent. Long-term resu ts of increased circulation in this area could be (1) more rapid flushing ofwaterborne constituents that have their r - 

### in zone 3 by Goetz and Goodwin (1980, p. 23). Physical changes in 

### zone 3 between 1880 and 1972 re-

o " • 

### between 1972 and 1985. Cumulative physical changes in zone 3 have reduced its natural constrictive effect and insion into the bay of constituents that have their source south of zone 3.

Zone 4 is a 4-mi-Iong region 0 

### greater average clrcu aIon an in a j culation increase ofabout 700 ft 3

### Is, or about 15 percent. In 1880, circulation in zone 8 was about 1,400 ft3

### /s. 

### volume, was tidally interchanged each day. Physical chan es between 1880 and 1972 caused an average circulation in 1880 was computed to be about 8,600 ft3

### Is. 9 3 

### interchan ed in zone 4 each day, or about 5 percent of the water volume in the zone. Zone 4 functions for Hillsborough and 

# a d Tampa ays In t e same way t a zone uncions a e r strict water and constituent interchange, as zone 3 does,

. This mixing contributes to rapid removal ofconstituents that have their source in the north and to rapid intrusion of constituents that have their source in the south. changes in zone 8 between 1880 and 1972 caused an avera e circulation increase ofabout 1,100 

### WIs, or about 79 percent. The increase in circulation at mi 9.5 (fig. 44) is due to effects ofthe Courtney Campbell Causeway (fig. 1). The circulation increase at mi 13 (fig. 44) is attributed caused a reduction in average circulation of about 700

3 

### An d itional reduction of about 100 ftJ/s 

### occurred between 1972 and 1985. The cumulative circulation reduction of9 percent in zone 4, accompanied by a 30-percent cumulative circulation increase in zone

, arge y er se 1880 to 1985. in circulation in zones 7 and 8 between 1972 and 1985 are com uted to be minor because no physical changes are expected. 

### Constituent Transport transport are developed in the model and presented in Model Results and Analysis 63

### this report in 

### a manner analogous to that used for water same as those chosen for water transport (see fig. 27). A 

# ..**:~** ••**~~,.l** ..**l.~** .. 1. 

## ., 

# . .. initial concentration distribntinn l'1m:plv 

# -_ ...

# - .... ' .......v. v •**ll;C:l~U** J 

### ,Jw-n ceu were near- • . th"t I., "t**~,,~** .... l\ t::. 1"**/~ ~..**  

# -.
. - ... •...**~""'p"** 

### measured for phosphorus in July 1975 (fig. 23). Constitu- Bay (site 1) for each level of development, varied from ent transport and flushing results presented in this report about 1.0 Ibis in 1880 to 0.8 Ibis in 1985 in mid-Tampa are appllCaOJe lor tms OIStrIOutIon only. Companson of Bay (site 9), varied from about 0.5 Ibis in 1880 to 0.7 results for 1880, 1972, and 1985 levels of development, Ibis in 1985 in Old Tampa Bay (site 23), and were nearly however, provides a means for assessing constituent- constant at 0.2 Ibis in Hillsborough Bay (site 18). transnort chanl!:es due to nhvsical chanl!'e!: in Tamna**'R~v** ,. ,**;~** 

### or direction at some sites for 1880, 1972, and 1985 levels Flood anti Fhh

- 

### of development are evident. Sites 6, 7, 16, 19, 24, and 25, for example, show changes due to construction of uuring r 10m 

### ow lor causeways, ISlanas, Channels, or submerged dIsposal 

# - 

# - - 1880, 1972, and 1985 levels of development are shown areas. in fijl;ures 45 46 and 47 resnectivelv Thellp. man!:**~hm"** 

## r, ,.l •• _:_ , c. 

# - 

# - -0 _ 

## ...

# - many similarities, including low constituent transport 1880, 1972, and 1985 levels of development are shown near the bay mouth, where concentrations are low, and in figures 48, 49, and 50, respectively. Ebb patterns, HIgn constituent transport In 

### the upper parts 01 

### the Day, although opposite in direction, are similar to the flo(])d



## .**,.~,** 

## . . in ngures 4)'-4/. 

### High constituent 

# ._----

...... "'6'" lUI; , dUU un**I;~- }.I"L'~'**  no> 

### /Snown tions ofconstituent-transport vectors at 25 selected sites transport occurs in the upper parts of the bay, and low during floodtide are listed in table 15. The sites arp thp
.**n('('nr~ np~r**  th
....... "'..th. Table 15. Constituent transport and direction during typical floodtide at selected sites in Tampa Bay for 1880, 1972, and 1985 levels of development Transport Direction

Site no. (pounds per second) (degrees, clockwise from north) (see fig. 27) 10nr,**,~-~ .~**  'L OJVJ 100U .:J/L J'It!:. 1



## --------------------------- 0.626 0.611 0.598 115 115 116 2 .406**~S17 ~7"**  1::0 ,en ..n 

### ---- ---- -- - 

### -------- 3



## --------------------------- .152 .143 .143 65 64 64 4



## --------------------------- .298 .346 .355 49 48 48 5



## --------------------------- .576 .631 .692 51 48 48 6



## --------------------------- .205 .161 .163 45 85 85 7



## --------------------------- .688 .595 .377 44 41 42 0 .:11 31 31 

### ---- --- ----- ---- - .JJ'" ..:"'.:> .:>-'0 9 07') n')o '111:.'1 "0**~~** 

### --- ----**~v** "'0 

## "'

... 10



## --------------------------- .688 .650 .679 29 30 31 39 38 38 

# .. - - -- -- - ---- 

### ----- 

## .,,,, ./S.:I4 ./SI/S 12



## --------------------------- .708 .670 .648 16 14 14 13


### -- - - ----- -- -- -- 1.10 1.17 1.24 IQ 17 

# '" 14



## --------------------------- .439 .395 .373 59 59 59 'J 

## --------------------------- l.ol/S 1.47 1.36 62 55 55 16 1.08 1.71 1.63 .,.:1 '10 ,A 

### -- -- - --- - ------ -- 17



## --------------------------- .842 .761 .542 6 31 355 18



## --------------------------- .238 .161 .170 336 345 348 19



## --------------------------- .582 .163 .320 348 346 30 20 1.81 21l 20Q**~"o** '1,11:. '1 ell:. 

### --- - - ---- - --- 

## -- 21



## --------------------------- .723 .571 .562 347 337 337 ')') , 316 316 

### -- -- --- - - --- --- •.• v !. 1'+ L I! .:IU 23 .:1QIl 1::111 1::7f\ "no**"n~** "n, 

### --- -- "UJ "uv 24



## --------------------------- .139 .207 .203 251 280 280 25



## --------------------------- .688 .368 .364 304 348 348
64 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Floridaical floodtide in Tam a Sa for 1880 level of development. " TRANSPORT VECTOR WITHOUT NODE EXPLANATION LOCATION OF MODEL COMPUTATION

4 I 2 I a I VECTOR MAGNITUDE DEFINED BY LENGTH OF LINE

VECTOR DIRECTION DEFINED FROM NODE LOCATION SYMBOL TO END OF LINE

• LOCATIONS OF TRANSPORT SITES LISTED IN TABLE 151SEE FIG. 27 FOR SITE NUMBERSt

5 MILES 4 

### o ............ ", , 

### --........................... . 

### .. 

# ............... - ,.,"' - - 

# .

.... ,,,,,"', . 

# · . 

# · ..



# ·....

Model Results and Analysis 655 MILES SYMBOLS ARE SHOWN FOR 25 PERCENT

4 I 2 I 

### o I VECTOR MAGNITUDE DEFINED BY LENGTH OF LINE

VECTOR DIRECTION DEFINED FROM NODE LOCATION SYMBOL TO END OF LINE TRANSPORT VECTOR WITHOUT NODE L LOCATION OF MODEL COMPUTATION SITE (NODEI

TRANSPORT VECTOR WITH NODE LOCATION SYMBOL

4 

### o 

# ... .

# ..... ...........
figure 46. Constituent-transport pattern during typical floodtide in Tampa Ba for 1972 level of develo ment.

66 Tidal·Flow, Circulation, and Flushing Changes in Tampa Bay, Florida.. A**~. ,.:~**  

## \ ,



# \**I-':~:X** 

## ."\h 

# +' f.H**7,'./.:~"r::'"** 

# :.:**:~~..** tXI"'LANAllUN**l"""\l~** '".;'**~X'** liZ**Z~///,··** ...

### ~:~~ "'" I

### ,.,:r~ 

# +:**r~ ~7~~:':'**  • LOCATION OF MODEL COMPUTATION

### I-t-;-~~Ml~-_.r---=**.-..~----rl"l'lil"j.-;: :;tI1ti~ltHrttm,,~,~**  

# ':::u "'T<: IlIJnn<:1 11 0**~:** : :**~~:** .,**~~** : ,.. 

# "I:
.: Z

### 'l**,~,** "':1**SYMB?~L;;** A!,E**~~OWN** FOR 25**~PERCENT ~"''O**  

### ...---....... ..**\...~~** 

### ...**~&"-'-"** .. ... -"--'--'11: ..**~c-=------------t-'1.** ,----0+.

I**~p'H-'-'H:1,1,~** 

# J,I',:jif"-**~' ,~~~~** **~,~ ,~~~~** **~~r** 

## ::: ::: ::**~"':'** 

## .. ::::**~,** 

## A'; : 

# i+**t~7;:'J/i!** 

# !:: : ... '- TRANSPORT VECTOR WITH NODE

.. . .. .. .. .. ',.....
........... '
.. ., II

## ,1/ 'I**~lj~:lr.** I I, • LOCATION SYMBOL • . • • • • • • • . • • '111 

## I"" ....... .•.•.•.• I • I 4 I IJ**11~1,6,** I ••



### ... .. '.)('11'" ///'////////Ilill**"~~:~:Y' ~~.** 

# .. L.U ""UN ., r1VH'UL. •.•.•.•.•.•.• , •.•. • ' .. .,W'''./ ...**/~/~/~J~/** ..

# ··-····'1 

# q

.. - ....••••••• , • • • "////,;"//JI//" r III I I I ; ie.,;;.,
. . . . • LOCATIONS OF TRANSPORT SITES LISTED IN •.•.•.•.•.•.•.••• ,**.'o'/r/o'/rf/"/"/"""'."~.A** J..

: : .•. :. .•••••• "_ ....**//-;/'~'** // // / /I I , , , I , , •• : . : :-... .....**:~** .-Iii TABLE 15 (SEE FIG. 27 FOR SITE NUMBERS)**Fi~ure** 47. Constituent-transport pattern during typical floodtide in Tampa Bay for 1985 level of development.

Model Results and Analysis 67

# ·
' 

# ·

- 

# . 

# · . ,.

# .. 

# ... ' 

# . o 3 4 1.

VECTOR MAGNITUDE DEFINED BY LENGTH OF LINE

VECTOR DIRECTION DEFINED FROM NODE LOCATION SYMBOL TO END OF LINE LOCATION SYMBOL

• LOCATIONS OF TRANSPORT SITES LISTED IN

TABLE 16 (SEE FIG 27 FOR SITE NUMBERSI

5 MILES
Figure 48. Constituent-transport pattern during typical ebbtide in Tampa Bay for 1880 level of development.

68 Tidal·Flow, Circulation, and Flushing Changes in Tampa Bay, Floridain Tam a Sa for 1972 level of develo ment.**-~---** 

### ........ 

# --- /**~,** 

### .. 41-..4-- " •••.• '

.....

# _--------", "'" 

### .. ",., 

## .... 

# .**~..............** 

# ·,...........-_..&-...- 'A ....... ;.o' ••



### .**:.:~: ~;** **~:~:~:~** 

### ..**j;';Z=~:~:~:~:~:~:~;;:;:~** 

### .•

### o.:··

......... -

### --....::**~/..,.,.--** 

### -- 

### --- 

### ----- - .

• • .. .. I , • • • • • • • •

• i ••••••

........ , I' ••• • 

# · , 

# . 

# · . 

# ·

# .. - 

# .

Fi ure 49. Constituent-trans 

### o 4 EXPLANATION OF MODEL COMPUTATION SYMBOLS ARE SHOWN FOR 25 PERCENT OF NODES TO AID VISUAL CLARITY ). TRANSPORT VECTOR WIThi NODE LOCATION SYMBOL

VECTOR MAGNITUDE DEFINED BY LENGTH OF LINE 

### o 2 4 I I I POUNDS PER SECOND VECTOR DIRECTION DEFINED FROM NODE LOCATION SYMBOL TO END OF LINE

" TRANSPORT VECTOR WITHOUT NODE

• LOCATIONS OF TRANSPORT SITES LISTED IN

TABLE 1 SEE IG. 27 R SITE NUMBERS

5 MILES

Model Results and Analysis 69SYMBOLS ARE SHOWN FOR 25 PERCENT

5 MILES VECTOR MAGNITUDE DEFINED BY LENGTH OF liNE 4 I 2 I o IEXPLANATION LOCATION OF MODEL COMPUTATION SITE (NODEI

• LOCATIONS OF TRANSPORT SITES liSTED IN TABLE 16 (SEE FIG 27 FOR SITE NUMBERS)

VECTOR DIRECTION DEFINED FROM NODE LOCATION SYMBOL TO END OF liNE

" TRANSPORT VECTOR WITHOUT NODE ..... TRANSPORT VECTOR WITH NODE LOCATION SYMBOL

4 

### o 

# ............... .**~/** 

### ........-.-

# ..-

## ..-**-.~** 

# .

: : 

### : : : 

### :**~:** - /-"--::-;: 

### -: 

### -: -: -: .. 

### : :
- : . 

# · ' ' 

# · . 

# · .



# · . 

# ·

.

# . .

# . .

# ..

# . .

# ..

# ..

# ... 

# ... ----......,

# .. 

# .**~-----~~** -- _/.,,1// I •• 

# .- "./

# .. ,. 

# .

Figure 50. Constituent-transport pattern during typical ebbtide in Tampa Bay for 1985 level of development.

70 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

### As with water transport, maximum constituent trans- tween 1972 and 1985 are shown in figure 52. Comparison port dunng ebbtlde IS substantially greater than that dur- offIgures 51 

### and 52 

### wIth hgures 33 

### and 34, 

### respeCtIVelY,

• • P 0 0 .. • 

### . 

# . - . HI!:> lUI; llUI; VI W,UI;I-II;VI;I II> 

### snows IOClL 

### sunuar r**~~H<1H!:>~** W<1C,,1 

### faster than the rate of water-level rise (fig. 22 and table and constituent transport during floodtide. This similarity 9). The malZnitudes and directions of constituent-trans- is exnected because constituent transnort is the product port vectors at 25 selected sites during ebbtide are listed of concentration times water transport and because the in table 16. Vector magnitudes through each 1,500-ft cell initial constituent concentrations used for each simulawere nearly constant at about 1.8 Ibis 

### at the entrance to tion were the same. The following table summarizes the



# .. o 0 o '" 

# . -' 

## . 

# - I <1UI}J<1 U<1,. \I>U.. IJ IVI**I;C1~H** I"VI;I VI**.~** , '<1111;'" 

### LOLal an:a auu r IVI uaUi)- 

### from about 1.5 Ibis 

### in 1880 to 1.2 Ibis 

### in 1985 in mid- port during floodtide between 1880 and 1972 and between Tamna Bav (site 9) varied from 0.6 Ibis 

### in 1880 to 0.9 1972 and 1985. The data confirm the lZeneral similarity Ibis 

### in 1985 in Old Tampa Bay (site 23), and remained to water transport during floodtide (see p. 49 ). nearly constant at OAlb/s 

### in Hillsborough Bay (site 18). Constituent transport, floodtide**I:I~** .... .... 1: .... Area of change, in square miles For 1880, 1972, and 1985 change 1880 to 1972 1972 to 1985 'nf" ti II 1'_ 

### 0-10 260 397



### - - 

# . . 11-50 144 

### 41 

### inlZ floodtide conditions for 1880 1972. and 1985 are 

### ------ shown in figures 45, 46, and 47, respectively. Changes ' I-IOU

_____ :>L, 0 

### in constituent transport for a typical floodtide between 101-200



### ----- 7 1 >200 1 0 IOOV 

### anu 1-' I '" 

### are SnOwn in Iigure .} I, 

### anu --- uc;:- Table 16. Constituent transport and direction during typical ebbtide at selected sites in Tampa Bay for 1880, 1972, and 1985**IC"C'~** v. Transport Direction

C' " L



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## --------------------------- 1.86 1.82 1.76 290 290 290



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## --------------------------- .353 .397 .395 229 266 266 7



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Model Results and Analysis 71**,I."'-....::.-:c".~** xx ....**l~OL-'"** 

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Figure 51. Changes in constituent transport in Tampa Bay for typical floodtide between 1880 and 1972 levels of development.

72 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

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Model Results and Analysis 73Transport patterns ofa representative constituent dur- Progressive constituent-transport reductions throughin fi ures 48, 49 and 50, res eetivel
. Fi ure 53 shows changes in constituent transport between 1880 and 1972, and figure 54 shows changes between 1972 and 1985. As reductions in water trans ort fi. 37 . Constituenttransport values and percentage changes among levels of development are given in table 17 for the seaward end WI 00 1 e con Ions, e e con 1 Ions pro uce patterns ofconstituent-transport change that are similar to patterns of water-transport change (see figs. 35 and 36 . The followin table summarizes the total area and o eac ay su area. ompanson 0 percentage-c ange figures between water and constituent transport, tables 12 and 17, respectively, shows a substantial difference onl at the seaward end of H' r h percentage changes for constituent transport during ebbtide. The values are generally comparable to those for 1880 and 1972. This difference indicates that constituent concentrations in Hillsborough Bay during the simulaIon peno 0 ours were re uc more or an

transport patterns for 1880, 1972, and 1985 levels of were not sufficiently long, however, to determine e uilibrium concentrations for each level ofdevelo ment. Percentage

0-10



### ------ 276 399 51-100



### ----- 53 7 101-200



### ----- 6 1

>200



### ------ 0 0 Figure 55 shows flood and ebb constituent transport for each cross section along longitudinal summary lines (see fig. 26) for 1880, 1972, and 1985 levels of developseries ofcirculatory features or gyres found for residual water transport (see figs. 38-40). Vector magnitudes defining constituent-transport gyre intensity are different 1 • g W spo gyre in ensi y ecause low at the Gulf of Mexico but increases to a maximum of the influence of the concentration distribution. The Residual constituent-transport vector magnitudes and directions are given in table 18 for 25 selected sites (see

. i w c per parts ofTam a Ba in areas ofhi h concentrations. is divided between zones 5 and 7. Constituent transport decreases to zero at the head of zones 6 and 8. Typical at the upper end of zone 4, where subsequent transport

(site 9), to range from 0.03 Ibis in 1880 to 0.07 Ibis in 1985 in OldTampa Bay (site 23), and to range from 0.06

. s oroug ay si e puted to be about 0.17 Ibis at the entrance to Tampa Bay (site 1) for all three levels ofdevelopment, to range from 0.04 Ibis in 1880 to 0.03 Ibis in 1985 in mid-Tam a Ba distribution that is very similar to but oflesser magnitude than that for ebb conditions. Maximum values reach about 24 Ibis for 1880 and 22 Ibis for 1985. The change in transport at mi 37 in figure 55 for 1972 and 1985 conditions corresponds to the location where tide-induced

Table 17. Flood and ebb constituent trans for 1880, 1972, and 1985 levels ofdevelo ment Percentage change 1880 1972 1985 to to to 1972 1985 1 During typical floodtide, computed at the seaward end Lower Tampa Bay

_____________ 5.22 4.93 4.89 

### - 5.6 -0.8 

### - 6.3 Middle Tampa Bay

____________ 13.7 13.1 13.0

- 4.4 - .8 

### - 5.1 Old Tampa Bay

_______________ 13.9 13.3 13.2 - 4.3 

### - .8 - 5.0 Hillsborough Bay

______________ 9.46 8.29 7.71 -12.4 -7.0 -18.5 During typical ebbtide, computed at the seaward end



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# ----------- Old Tampa Bay

_______________ 15.6 14.8 14.6 - 5.1 -1.4 

### - 6.4 Hillsborough Tampa Bay

_______ 14.5 13.1 12.3 - 9.7 -6.1 -15.2

74 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

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Model Results and Analysis 75PERCENTAGE CHANGE EXPLANATION

0-10 

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Igure 54. C anges in constituent transport in Tampa Bay for typical ebbtide between 1972 and 1985 levels of development.

76 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida**3'tr--~---------------------'** I**I~** 

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### o 5 10 15 ZO ,;)**~a** DISTANCE FROM MODEL BOUNDARY IN GULF OF ME)(ICO. IN MILES Figure 55. Constituent transport along longitudinal summary lines (see fig. 26) during typical floodtide and ebbtide in Tampa Bay for 1880, 1972, and 1985 levels of development.



# .. .**~...-** 'lll
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### firm the general similarity with areas ofchange computed fnr rf"l:idual water transDort (D. 

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.... ' L For 1880, 1972, and 1985**~c ~"7**  __ ...**~o** _,-_.. nl'" • ,..",n_

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### stituent transport for 1880, 1972, and 1985 levels of development, respectively. Areas of change in residual constituent transport between 1880 and 1972 are shown in figure 59, and changes between Pin 

### and**l~lS'** 

### are shown in figure 60. As with previously discussed differ-

,. "71

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### similar. Comparison offigures 59 and 60 with figures 42 and 43, respectively, shows the similarity ofpatterns. The following table**summan~s** 

### the total area ana percentage Percentalle change 0-10

_ 

### 11-50

__ 51-100

_ 101-200

_

>200

_ Residual constituent transport Area of change, in square miles 1880 to 1972 1972 to 1985 

### 98 241 166 144 IS'; ;'6. 72 

### 24 45 6
Model Results and Analysis 77

# 1\ , 1J 

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• LOCATIONS OF TRANSPORT SITES LISTED IN

TABLE 18 ISH FIG 27 FOR SITE NUMBERS)

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78 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

### o 4 LOCATION OF MODEL COMPUTATION SITE (NODE) SYMBOLS ARE SHOWN FOR 25 PERCENT N DES TO AID VISUAL CLARITY

VECTOR MAGNITUDE DEFINED BY LENGTH OF LINE 

### o 0.2 0.4 I I I POUNDS PER SECOND VECTOR DIRECTION DEFINED FROM NODE LOCATION SYMBOL TO END OF LINE TRANSPORT VECTOR LOCATION SYMBOL LOCATIONS OF TRANSPORT SITES LISTED IN TABLE 18 (SEE FIG. 27 FOR SITE NUMBERS)

5 MILES Figure 57. Residual constituent-transport pattern in Tampa Bay for 1972 level of development.

Model Results and Analysis 79I I I POUNDS PER SECOND VECTOR DIRECTION DEFINED FROM NODE LOCATION VECTOR MAGNITUDE DEFINED BY LENGTH OF LINE 25 PERCENT OF NODES TO AID VISUAL CLARITY T R WITH NODE LOCATION SYMBOL

(SEE FIG. 27 FOR SITE NUMBERS I EXPLANATION

• LOCATION OF MODEL COMPUTATION SITE (NODEI

• LOCATIONS OF TRANSPORT SITES LISTED IN TABLE 18 " TRANSPORT VECTOR WITHOUT NODE LOCATION SYMBOL

5 MILES 4 

### o

In Tampa Bay for 1985 level of development. .- ... " : : : : : : : : : : : '21°30'

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80 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

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Tam a Bay between 1880 and 1972 levels of development. '" 

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Model Results and Analysis 810-10

>200 11-50 51-100 PERCENTAGE CHANGE EXPLANATION



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# . t.' II ••••

Figure 60. Changes in residual constituent transport in Tampa Bay between 1972 and 1985 levels of development.

82 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaTable 18. Residual constituent transport and direction at selected sites in Tampa Bay for 1880, 1972, and 1985 levels of development Site no. "" "I-'V' , (degrees, clockwise from north) (pounds per second) (see fig. 27) 1880 1972 1985 1880 1972 1985 1



## --------------------------- 0.177 0.168 0.167 288 287 285 2



## --------------------------- .032 .031 .028 119 118 130 3



## --------------------------- .025 .024 .023 60 60 60


# .. - -- 

### ------- - 

## ----------- .vn' .VH\ .Vll**~V** 1" 1"0 5



## --------------------------- .015 .023 .040 334 309 290 6



### --------------------------- .006 .034 .032 291 265 264 I


### --------------------------- .Vj
..**.Vj~ .V~I** **~~o ~::JI** **~~** 8



## --------------------------- .056 .054 .050 179 177 177 9



### --------------------------- .038 .040 .029 

## n 63 220 10



## --------------------------- .022 .043 .038 310 286 289
11 n..,L n..,o n..,c ..,nc "'1.., 'In



### - ------ - - - - ---- 12 .040 .037 .033 192 228 219 13



### --------------------------- .057 .071 

## .on 344 357 9 14



## --------------------------- .on .on .068 261 259 257 IC I
... '''\c I.,n ,c., 

### ,

# .... 1..,';; 

# . -- ------ 

### ---- - --- --- 16



### --------------------------- .032 .380 .774 83 59 59 17



## --------------------------- .020 .043 .145 3 229 280 In ,,,

# .**A~n** A .... .nn ,

### ...., , ...L .u 

### - ---- - • vV' .V..u 

# '. .uu 'oJ 19



### --------------------------- .025 .032 .088 284 149 74 20



### --------------------------- .070 .111 .108 58 194 195**~--** 

# -- 

# --**~, ~1**  .V· .VIO .V**;)~ ~v**  ..v 22



## --------------------------- .093 .203 .201 290 282 283 23



## --------------------------- .028 .071 .070 179 78 78 24



## --------------------------- .019 .066 .064 210 189 189 25



## --------------------------- .043 

## .on .071 278 86 86
Tide-induced flushing, for purposes ofthis report, can 1972, and 1985 are given in table 19 (see fig. 26 for locah", .,..**,,~** tnt,,! .**(~"''''** T •••**.:~~ ~f'** **~~~O,.\** Summarv section n. 37) minus the constituent trans- Averal!:e tide-induced flushinQ: chanQ:es in zones 1 2 port caused by tributary streamflow. Figure 61 shows and 3 are generally consistent with tide-induced circulaboth computed tide-induced and streamflow flushing for tion changes shown in table 14. An overall tide-induced HSISU, 1'111., ana I'JIS' levelS 01 aevelopment. KeSUltS are Ilusning or less man 1 .Ul ZUlU; not given for Old Tampa Bay because tide-induced 1; an increase of about 41 percent occurred in zone 2, ·ic: ,.,. •. 7prn r1I1P tn t'nn_**~mrl** !'In . nf !'Ihnl1t 1 Ii. in 70ne stituent distribution (see fig. 23). For the constituent used For the examole constituent distribution, a flushing in this study, concentrations are highest near the head minimum occurred in zone 2 in the lower part ofTampa of Hillsborough Bay (see fig. 23) and decrease toward Bay (fig. 61 and table 19), whereas a circulation minimum me \JUn Or NleXlCO. ;,ucn a aismoudon proauces larger 

## . . 1Il zum: j \llg. '+'+ ana laOle l'+}. flushing by streamflow in Hillsborough Bay than in lower A computed 14-percent increase (table 19) in tideTampa Bay (fig. 61). induced flushing between 1880 and 1972 in zone 4 is difFor the examole constituent tide-induced flushing is ficult to understand because computed tide-induced cirgenerally low, between 2,000 and 6,000 Ibid in zones 1, culation decreased by about 8 percent in the zone during 2, and 3 for all three levels of development (table 19). the same period (table 14). The cause for this condition

,. 

## . . . . LUUC 't**i~** <111 i:11Ci:1 Ul**Ui~l1liuc-** 

### ,**1~** llU1\.CUlU 111
. 111 ,,"vu\,o ... , C**.~A** L .f' • 1_ 

## .- .,...:A_**~~A --~-**  

### .., 1001\

__ A 10.,,, T:rl
.. 

# ..

# -**~.~ ~.~~~**  

# ... 

# . . , induced flushing for 1972 and 1985 conditions is generally induced flushing is determined both by circulation and greater than for 1880 conditions. Average flushing for the distribution of constituent carried by the circulating each zone in the bay and percentage changes among 1880, water. Therefore, the amounts of constituent material Model Results and Analysis 8330 I I I I


# - - 

# - ... 

# .. ., 

# .. 1"-' 

### .-: > 25 

## ,'......J**z~** 

### 1/

.... I I ltR5U 

### , 

# If: , 

# I=t

-------- 1172 II) 20

..................-.. 1986 /.: 

### z· I.: 

### l

## 8~ - r-'Dr-III .fl.TlnAl 

## f l POSITION OF ALAFIA w;::) I I ZONE 

# .f
. 

## 1\ HIVt:H MOUTH IN: I 

### it 

## 2 16 BOUNDARY !' J I 

### , \ :, I /\.,.,....1972 AND 1986**~~** " I

### ~;:: 

# l \

## ":~ 

# ; i h' 

# V 1880

### ~!i 

# .iI**~,** rjl....**/~** 

## , I I ••.• \ 

# t'r**'~V** !\ \ Cl 10**.~** I'. \. , Ii 7;::) 

## ... \. 

### , 

### .

# ~~

# ~a .....

# ;;;;;;

.............

# ~/**~~** i I
.. \ I \. UCIEO 

# ,---:::w \, 1**~. ~z**  

### " '
...._... -"".... f:LUSh'a

. I.. I



## ... .........**~;~** .......... 

### .. 

## _ Y-,:
...R'{**S"t1'eJ''''''~** 

# '"

'-..... I I:' 

## \
..'**'.~** -.:/'" '- 

# - 

# --

- E"AGE 

# "''''0\,1 \ 

# \**~.---** I--fLUSHING 8'{ A"**'~** __I \**~.** 0 ,- I I I i '\ I I I I , ..... i.


# .. IU 10 I.U oLD "u "0 DISTANCE FROM MODEL I!IOUNDA"V IN GULF OF MEXICO, IN MilES Figure 61. Tide-induced and streamflow flushing ofexample constituent along longitudinal summary line (see fig. 26) from lower T;tmn;t R;tv tn . R;tv fnr 1AAI'l 1Q7? :lnrl 1QAt; f"""ic nf flushed into zone 4 from zones 5 and 7 orobablv caused tween 1880 and 1985. Streamflow however remained the significantly different constituent distributions in 1972 dominant flushing mechanism in zone 6. ano HSlSU.rne computeol'lIl. CllstrlbutlOn was apparently This analysis shows that changes to Tampa Bay since sufficient to more than offset the reduced 1972 circula- 1880 have generally increased tide-induced flushing of a**+~_~** A A**:~** 'oJ 

### .**~,** 

# - . 

## .. 

# .- v ... u<,: V 1U5 <': 

### - curred in zone 4 between 1972 and 1985. tion similar to that shown in figure 23. Most increases In zone 5, streamflow and tide-induced circulation pro- were caused by physical changes in the bay between 1880 duce about equal rates of flushing for the example con- and 1972. Assuming that streamflow and upland constistltuent. ComputatIons mdlcate that poweq,fant c06Iing- tuent inflow remain constant, this greater rate offlushing water circulation and other physical changes will produce will cause lower concentration levels throughout the bay
.**_~** _ .. d¥_11 •

.**:~** . ., .1- 

### .,.., 

# ... ,. 

## . . . .

_.. v ... vv .. oJ ... "v ,... ... .... ,,'" .. II:>'" lU , <':llUU nercent bv**19~'i** t.." ..**l~** nf th"t h"".. ' In 1880, the primary flushing mechanism in zone 6 was tributary streamflow. Powerplant cooling-water circula- (;.IIUU"RY tlon at ID1 j() {see 1Ig. ()l), ShIp-channel constructlOn, and shoreline filling expected through 1985 contribute to tide- Changes in two-dimensional tidal flow, circulation, and



## . 

# . 

# .... , 

## . "f
..... " ..... ,1.**_~** ., CI\ 1._ • ._ .n_...I 1.. -I¥. ,-I. ....1 ":11 .. 

# .. 

# - ' J ••

# --0- ..-.. • .. £ "''''p'' Table 19. Tide-induced flushing and percentage changes in Tampa Bay for 1880, 1972, and 1985 levels of development Circulation Average tide-induced flushing Percentage change zone (see (pounds per day) 1880 1972 1880

fig. 26) 1880 1972 1985 to to to 1972 1985 1985 1 5,930 5,830 5,890 - 1.7 + 1.0 

### - 0.7



## ---------------------------- 2



### ---------------------------- 2,560 3,320 3,740 + 25.3 + 12.6 +41.1 1 n '" " ,on " .,.,n C C ,n , " " J 

### - -- ------ ----- - ---- - 

### , 

# . J, 

# . .**.v.~** 4 11'\100 HL'iI'\O 17.900 + 13.9 1 1'\ -I- Qll 

### - --- - ----- - 5



## ---------------------------- 7,070 9,830 9,650 + 39.0 

### - 1.8 + 36.5 6


## ---------------------------- 1,150 3,950 4,100 +243 + 3.8 +257
84 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida

### 3. circulation computed for adjacent bayward and seaward areas. Circulation in an area seaward ofthe entrances to

eac Ig an ow Clrcu a Ion zone. Tide-induced circulation increased throughout most of tion either at or seaward oftheir respective bay entrances. Each also has a zone oflow circulation at some distance bayward oftheir entrances. A zone oftransition separates decreased to zero at the heads of Hillsborough and Old Tampa Bays.

tree-zone sequences ave a so been IdentIfIed and



## . . Bay system. Tampa Bay, Hillsborough Bay, and Old Computed circulation between middle and lower Tampa Bays, an area of apparent circulation constriction, ranged from 4,900 ft3

### /s (1880) to 6,300 ft3

### /s (1985), lower than

Eight zones have been identified on the basis of tideinduced circulation characteristics 

### in Tampa Bay. Three or tidal prism, caused b fillin ofthe ba
. Hillsborou h

u e ana u 7 percent from 1972 to 1985. Hillsborough Bay also had the largest percentage reduction in tidal prism. Dredged and filled areas have changed the magnitude Bay are determined in this study by using**finite~ifference**

P ysica changes to the bay; 2. conditions in 1972 after construction of numerous causeways, islands, shoreline fills, and a series of men were c osen or companson: 1. conditions in 1880 prior to any significant manmade computer simulation techniques. Three levels ofdevelopand direction of tidal floodflows and ebbflows in large parts of the bay. Areas near islands, causeways, chanBay has had the largest changes in tidal flows. Flow reductions into and out of Hillsborough Bay were compercent over about 58 mP ofthe bay from 1880 to 1972. Similar changes from 1972 to 1985 occurred over only 8 mP.

Residual water-transport maps for each level of development show a sequence of about 20 circulatory curred in the upper part ofHillsborough Bay from 1880 to 1972. A 15-percentincrease was computed for that area for 1972 to 1985. In the zone ofcirculation constriction, between middle and lower TampaBay, increases of6 and 22 percent occurred from 1880 to 1972 and from 1972 have a large influence on the long-term interchange of water and constituents between sections of Tampa Bay and between the bay and the GulfofMexico. The overall tion were caused by pumping for powerplant coolingwater systems. A reduction of about 4 percent in tideinduced circulation occurred near the mouth of Tampa clrcu atlOn patterns m , an are VIsua y similar, with some areas of obvious differences, mostly ay rom 1 to 1972. A reduction of about 6 percent occurred from 1972 to 1985.
was investigated in this study. The constituent distribution used in the model a roximated that of hos horus measured in July 1975. Highest concentrations, 1.5-2.5 mg/L, were in Hillsborough Bay. Concentrations were nearly constant at 0.8 mg/L in Old Tampa Bay and dereas 0 reSl ua water- ranspo c ange are severa times largerthan those computed for tidal flood- and ebbborough and Old Tampa Bays due to dredge and fill activity. Another area oflarge residual change from 1880 shape can be distorted by these physical changes. be reduced or increased, gyre location can be shifted, new gyres can be created, old gyres can 

### be destroyed, and gyre

resi en i ,causeway, an s IP-C anne cons ruc IOn. From 1972 to 1985, Hillsborough and lower Tampa Bays to 1972 was lower Tampa Bay; the increase was due to cent occurred in about 167 mP from 1880 to 1972. About 57 mP were changed by the same amount from 1972 to 1985. Between 1880 and 1972, large residual waterand island construction. tidal fills. Summary 85

### Residual constituent-transport maps show gyre features sImIlar to mose compurea ror reslaual water transport. 

## ,.. 

# . Vl;l,;lUI i111;
.... v ...v.**IdI~l;a,** , 

### for those gyres in regions ofhigh constituent concentration :md 

### Iv smaller in rellions of low concentration. Areas ofcomputed change in flood, ebb, and residual constituent transport are in all respects very similar to the corresponding changes computed for flood,


# . . . I;UU, CUIU ""4L\;1 

### In most areas ofTampa Bay, constituent flushing of the examnle constituentinduced bv the tide is ereater than that induced by streamflow. In most of Hillsborough Bay, particularly the upper part, flushing by streamflow is larger than tide-induced flushing for all three levels of



## .. , • J.IU\;- 

### throughout most of the bay in 

### response to physical chanees that have been made since 1880. The 2reatest tide-induced flushing increase, 243 percent, occurred in Hillsborough Bay from 1880 to 1972. A 4-percent increase occurred in Hillsborough Bay from 1972 to 1985. In a I."
....... , .1." LV ..... V' O' 0
...V .. .," ...... V ..... L
....... 11 .......... v, 

### lower Tampa Bay, tide-induced flushing increased 25 percent from 1880 to 1972 and 13 percent from 1972 to 1985. Large local increases in flushing were caused by pumping for powerplant cooling-water systems. As a result ofincreases in tide-induced circulation and ..1.

o 

### borne constituents that have landward sources to the Gulf of Mexico. Conversely, the bay can also more rapidly transfer constituents that have their source in the Gulf into the upper parts of the bay. 

### SELECTED REFERENCES April, G. C., Hill, D.O., and Liu, Hua-An, 1975, Hydrodynamic and material transport model for Mobile Bay,

, ITI Ull American Society ofCivil Engineers Conference, San Francisco, Calif., September 3-5, 1975, Proceedings, p. 764-782. Beauchamp, C. H., and Spaulding, M. F., 1978, Tidal circula- t;roon ;n ,.,..,.,ot.,1 ..**.,~;"** .. . roof •**.,n~** physical models in hydraulic en2ineerin2: American Society of Civil Engineers Specialty Conference, College Park, Md., August 9-11, 1978, Proceedings, p. 518-528. T T C'. UT n , (\£n. ments at gaging stations: U.S. Geological Survey Techniques ofWater-Resources Investigations Book 3, Chap. A8, 65 p. F'L nTF'. , no"\ '"'- T '**.~.** 0.,

_**~_~_"" ~~,** **.~** ,_, .. residual currents with applications in south San Francisco Bay, California: Water Resources Research, v. 18, no. 6, p. 1652-1662.**~.** • • n A, ••**~11""!>,** n.. .., ..l1U U"1 L11"I, J. ., 170"', of tides and tidal currents in South San Francisco Bay, California: Estuarine, Coastal, and ShelfScience, London, Academic Press, v. 21, p. 52-74. Dinardi, D. A., 1978, Tampa Bay circulatory survey 1963: Nanonal ucean**~urvey** uceanograpnic drcUlawry**~urvey D,.~~**  ...**"T~'"** •**~"~** A . ArL

or ministration, 39 p. Dronkers, J. J., 1964, Tidal computations: Amsterdam, North Holland Publishing Company, 518 p. Elder, J. W., 1959, The dispersion ofmarked fluid in turbulent shear flow: Journal ofFluid Mechanics, v. 5, p. 544-560. Fischer H. B. List J. E. Imbenzer Jorl!:. and Brooks N. H. 1979, Mixing in inland and coastal waters: New York, Academic Press, 483 p. uiovanneui, 1\.. r., 1 "0 1, I\.elluiun UCLWa::n HUW dllU -, and Hillsborough Bay, Florida: U.S. Geological Survey Water-Resources Investigations 80-102, 68 p. Goetz, C. L., and Goodwin, C. R., 1980, Water quality of Tampa Bay, Florida: June 1972-May 1976: U.S. Geological SlIrvPV**WMpr_~** RO.. 12. 'i'i n. Goodwin C. R. 1977, Circulation patterns for historical, existing, and proposed channel configurations in Hillsborough Bay, Florida: International Navigation Congress, "'1,1,1.
.. I.'"**.~,** A**~~~** A " T";:'7 1'70

, "oJ' " , r" ---1980, Preliminary simulated tidal flow and circulation patterns in Hillsborough Bay, Florida: U.S. Geological Survey Open-File Report 80-1021,28 p. liooawm, L. K., ana Mlcnaells, u. M.,**l~/b,** naes m lampa Bay, Florida: June 1971 to December 1973: U.S. Geological Survev Ooen-File Reoort FL-75004 338 o. ---1984, Appearance and water quality ofturbidity plumes produced by dredging in Tampa Bay, Florida: U.S. Geological Survey Water-Supply Paper 2192, 66 p. •. i" D •• T**~"r1"** • T'\!lo.... 10'7A 

### , , Water quality of Tampa Bay, Florida: Dry weather conditions, June 1971: U.S. Geological Survey Open-File Report FL-74026, 85 p. .7 '"" ''''''I 'l.U"I11y Ul 1"1111-''' "'''y, CIVHU". ,,,,- weather conditions, October 1971: U.S. Geological Survey Open-File Report FL-75005, 88 p. Gren, G. G., 1976, Hydraulic dredges, including boosters, in ureaging ana irs env**eIIeC[s~** uv....... ] of Civil Engineers Specialty Conference, Mobile, Ala., January 26-28, 1976, Proceedings, p. 115-124. Heath, R. C., and Conover, C. S., 1981, Hydrologic almanac of Florida: U.S. Geological Survey Open-File Report 01 111\'7 "'1":10
, r' Hollev. E. R. 1969 Unified view ofdiffusion and disoersion: American Society ofCivil Engineers, v. 95, no. HY2, Proceedings, p. 621-631. T T T**,,'~ro** ..1_, r 

### ,J. J., OJ 'v, , ...... -"1
....... ]
...**v~** .... v. well-mixed estuaries and coastal seas: Volume I, Principles ofcomputation: SantaMonica, Calif., The Rand Corporation, RM-6230-RC, 71 p.**,n~"** r _"**,~,** ........ -"1
....... ]
...v ...... V. ' .... - .... A .. estuaries and coastal seas: Volume IV, Jamaica Bay tidal flows: New York, The New York City Rand Institute, R-l009-NYC, 48 p. ,**.,'~** 

## .
, J. J., "11"1 UI1L'Vll, J:..**~.,** 17 I, l"l> WdL"I-11UdllLY simulation model for well-mixed estuaries and coastal seas: Volume II, Computation procedures: New York, The New York City Rand Institute, R-708-NYC, 48 p. 86 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, FloridaJacksonville, Fla., 17 p. August 9-11, 1978, Proceedings, p. 500-508. 2656-2670. Wang, J. D., 1978, Verification offinite element hydrodynamic cee mgs 0 e IX een oas a ngmeenng on erence: U.S. Department ofthe Interior, 1969, Problems and management ofwater quality in Hillsborough Bay, Florida: Federal Water Pollution Control Administration, 88 p. U.S. Geological Survey, 1977, Water resources data for Florida, water year 1976: U.S. Geological Survey Water-Data Re ort FL-76- v. Van der Ree. W. J., Voogt, J., and Leendertse, J. J., 1978, A tidal survey for a model of an offshore area, in Promodel cafe, in Verification ofmathematical and physical models in hydraulic engineering: American Society ofCivil Woodward-Gyde Consultants, 1979, Egmont Channel, Tampa, Florida, tidal height study: Final report contract New York, The New York City Rand Institute, R-1586-NYC, 103 p.

e , Hydraulics Division, American Society ofCivil Engineers, v. 100, no. HY4, p. 517-529.

Bottom configuration and environment of Tampa Bay: Photogrammetric Engineering and Remote Sensing, v. 43, no. 6, p. 693-699. Conference, San Francisco, Calif., September 3-5, 1975,

and Harbors Division, American Society ofCivil Engineers, v. 94, no. WWI, p. 33-57. osens em, . ., 00 wm, . ., an ura 0, omo, eWls, ., an Itman,. L., 1985, new geographic description ofthe boundaries and subdivisions ofTampa Bay, in Tampa Bay Area Scientific Information Symposium, May 1982: Tampa, Fla., Proceedings, p. 10-17. Masch, F. D., and Brandes, R. J., 1975, Simulation of tidal hydrodynamics

- Masonboro Inlet, in Symposium on



### . 

## . Proceedings, p. 220-239. Prandle, David, and Crookshank, N. L., 1974, Numerical

specifically, the tidally averaged rate of inward-flowing water defined at any cross section within a tidal water body, expressed in volume per unit time. Due to continuity, this is also e ual to the tidall aver ed rate ofoutward-flowin body multiplied by the tidal range between high tide and low tide.
erm wa er mo Ion a occurs ecause 0 e exis ence 0 alternating flood and ebb (inward and outward) movement of the tide over an irre lar! sha ed bottom. More Mean lower low water. A tidal datum computed as the average ofthe lowest low water altitude ofeach tidal day observed epoch. a uantit of constituent material dissolved in water. expressed in weight per unit time. Dissolved constituent. Any material that is in true solution as Gyre. An area ofrotational water flow that is characterized by little or no motion near its center and generally circular or eliptical motion elsewhere.

Tide-induced circulation. In general, the tidally averaged, longTidal prism. The volume of water that enters or leaves a tidal water body between high slack water and low slack water.

water minus the average tributary streamflow. Water transport. The rate and direction of movement of aartsa a epor p. adjacent waters, August 1961 through December 1962: U.S. Fish and Wildlife Service, Bureau ofCommercial Fisheries Mexico: St. Petersburg, Fla., Florida Institute of oss, B. ., 1 3, e ydrologyand ushing of the bays, estuaries, and nearshore areas ofthe eastern GulfofMexico in A summar of knowled e of the eastern Gulf of

ceanography, p. IID-I-IID-45. Ross, B. E., and Anderson, M. W., 1972 Courtney-Campbell Department ofTransportation, Tampa Bay Regional Planning Council, St. Petersburg, Fla., 16 p. Saloman, C. H., Finucane, J. H., and Kelly, J. A., Jr., 1964,

Glossary of selected Terms 87Abbreviations and Conversion Factors

" , • ,0' n ". ' .n"

...... 'V
.. <v' -g**'~** u ..... u ..................pv .v , ..**].......-v~~IQ** Multiply inch-pound unit By To obtain Sl unit inch (in.) 25.4 millimeter (rom)

foot (ft) 0.3048 meter (m) mile (mi) 1.609 kilometer (km) ", .. <or....... ;1 .. (..... '2\ ., "'Of) o" .. <>r.. (1r..... 2'

cubic foot (ft3) 0.02832 cubic meter (m3) cubic yard (yd3) 0.7646 cubic meter (m3) 1001 per secona tHIS) U.jU<+lS meter per secona tm/s)

, L f.' fL' • £fV\ •

_ L

__ f1 ,/L'

...... t' w.**..~".** v ..., ,., t' <OJ pound per second (Ibis) 0.4536 kilogram per second (kg/s) pound per day (Ibid) 0.4536 kilogram per day (kgld) square loot per secona Vt'/S)**U.lH.l~** square meter per secona tm'/s)

cubic foot per second (ft3/s) 0.02832 cubic meter per second (m3/s) foot ner sauare second (ftIS2) 0.3048 meter ner sauare second lm/s2 ) pound per square foot (lb/ft2) 4.882 kilogram per square meter (kg/m2) pound-square secona per toot" (lb-S"/tt") 515.2 kilogram per cubiC meter (kg/m') micromho per centimeter at 25°C <ltmho/cm) 1.000 microseimens per centimeter at 25°C <ltS/cm) National Geodetic Vertical Datum of1929 (NGVD of1929). -A geodetic datum derived from a general adjustment of the first-order level nets of both the United States and' Canada, formerly called mean sea level.

88 Tidal-Flow, Circulation, and Flushing Changes in Tampa Bay, Florida '* us GOVERNMENT PRINTING OFPIC'K 1987
- 181-407
- 226}40110