U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2010–5003

Prepared in cooperation with the 

Federal Emergency Management Agency

Flood of April and May 2008 in 

Northern Maine
Cover. Aerial view of flooding in Fort Kent, Maine, May 1, 2008. (Photograph courtesy of Maine Department of Public Safety)
Flood of April and May 2008 in 

Northern Maine

By Pamela J. Lombard

Prepared in cooperation with the Federal Emergency Management Agency

Scientific Investigations Report 2010–5003

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2010

For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, 

natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS

For an overview of USGS information products, including maps, imagery, and publications, 

visit http://www.usgs.gov/pubprod

To order this and other USGS information products, visit http://store.usgs.gov

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the 

U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Lombard, P.J., 2010, Flood of April and May 2008 in northern Maine: U.S. Geological Survey 

Scientific Investigations Report 2010–5003, 17 p. at http://pubs.usgs.gov/sir/2010/5003/.
iii

Contents

Abstract ...........................................................................................................................................................1

Introduction.....................................................................................................................................................1

Antecedent Hydrologic Conditions ....................................................................................................2

Storm Characteristics ..........................................................................................................................2

Description of Flood.......................................................................................................................................7

Peak Water-Surface Elevations .........................................................................................................7

Peak Streamflows ...............................................................................................................................12

Exceedance Probabilities of Peak Streamflows ...........................................................................12

Comparison of 2008 Flood Data to Published Flood Insurance Studies .............................................16

Summary and Conclusions .........................................................................................................................17

Acknowledgments .......................................................................................................................................17

References Cited..........................................................................................................................................17

Figures

 1. Map showing location of study area .........................................................................................3

 2. Photograph showing flooding from Fish River at Soldier Pond, Maine, May 3, 2008 ........4

 3. Maps showing change in water content in snowpack (A) from April 15 to 22,

and (B) from April 22 to 29, 2008, northern Maine ...................................................................5

 4. Hydrograph of St. John River below Fish River at Fort Kent, Maine (U.S. Geological 

Survey streamgage 01014000), from April 22 through May 7, 2008, and streamflows 

of selected exceedance probabilities at this location ...........................................................6

 5. Map showing total storm precipitation from April 29 through 30, 2008, 

northern Maine .............................................................................................................................6

 6. Photograph showing flooding at International Bridge connecting Fort Kent, Maine, 

to New Brunswick, Canada, on April 30, 2008 .........................................................................7

 7. Map showing site numbers of surveyed high-water marks following the April and 

May 2008 flood in northern Maine ...........................................................................................10

 8. Photographs showing high-water mark identification and marking after the 

April/May 2008 flood in northern Maine: (A) debris line, (B) debris line along St.

John River dike in Fort Kent looking downstream at International Bridge, (C) debris

line on tree, (D) U.S. Geological Survey high-water marker, (E) setting high-water

mark along St. John River in Allagash, and (F) debris line on fence in Fort Kent ............11

 9. Map showing sites where peak streamflows were calculated for the April and May 

2008 flood in northern Maine ....................................................................................................14

 10. Map showing annual probability of exceedance for peak streamflows observed 

during the April and May 2008 flood at selected sites in northern Maine ........................15

Tables

 1. Identification numbers and locations for high-water marks in northern Maine from 

flood of April and May 2008 .........................................................................................................8

 2. Peak flows for selected exceedance probabilities and actual peak flows calculated 

for the April and May 2008 flood in northern Maine .............................................................13

 3. Relation of computed April and May 2008 peak streamflows and high-water 

mark elevations to flood-insurance study data at selected streamgages in 

northern Maine ...........................................................................................................................16
iv

Multiply By To obtain

Length

inch (in.) 2.54 centimeter (cm)

foot (ft) 0.3048 meter (m)

Flow rate

cubic foot per second (ft3

/s) 0.02832 cubic meter per second (m3/s)

Conversion Factors, Datums and Abbreviations

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 

(NAVD 88).

Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).

Altitude, as used in this report, refers to distance above the vertical datum.

FIS flood insurance studies

GPS Global Positioning System

HWM high-water mark

USGS U.S. Geological Survey

ABBREVIATIONS
Abstract

Severe flooding occurred in Aroostook and Penobscot 

Counties in northern Maine between April 28 and May 1, 

2008, and was most extreme in the town of Fort Kent. Peak 

streamflows in northern Aroostook County were the result of a 

persistent heavy snowpack that caused high streamflows when 

it quickly melted during the third week of April 2008. Snowmelt was followed by from two to four inches of rainfall over 

a 2-day period in northern Maine. Peak water-surface elevations resulting from the flood were obtained from 13 continuous-record streamgages and 63 surveyed high-water marks in 

Aroostook and Penobscot Counties. Peak streamflows were 

obtained from 20 sites on 15 streams through stage/discharge 

rating curves or hydraulic flow models. Peak water-surface 

elevations and streamflows were the highest ever recorded 

at seven continuous-record streamgages, which had between 

25 and 84 years of record in northern Aroostook County. The 

annual exceedance probability (the percent chance of exceeding the streamflow recorded during the April/May 2008 flood 

during any given year) at six streamgages in northern Maine 

was equal to or less than 1 percent. 

Data from flood-insurance studies published by the 

Federal Emergency Management Agency were available 

for five of the locations analyzed for the April/May 2008 

flood and were compared to streamflows and observed peak 

water-surface elevations from the 2008 flood. Water-surface 

elevations that would be expected given the observed flow 

as applied to the effective flood insurance studies ranged 

from between 1 and 4 feet from the water-surface elevations 

observed during the 2008 flood. Differences were likely the 

result of up to 30 years of additional data for the calculation 

of recurrence intervals and the fact that hydraulic models used 

for the models had not previously been calibrated to a flood of 

this magnitude. 

Introduction

Records and analyses of peak water-surface elevations 

and streamflows resulting from extreme rainfall and snowmelt 

events are crucial for determining the annual exceedance probabilities associated with these events. These probabilities are 

necessary to provide appropriate disaster-assistance funding 

and guide mitigation measures to minimize losses in future 

floods. In past flood reports, flood frequencies were expressed 

as recurrence intervals for selected flood quantiles such as the 

“100-year flood.” The use of recurrence-interval terminology 

is now discouraged by the U.S. Geological Survey (USGS) 

because it sometimes causes confusion for the general public. 

Recurrence-interval terminology is sometimes interpreted to 

imply there is a set time interval between floods of a particular 

magnitude, when in fact, floods are random processes that are 

best understood using probabilistic terms. 

The use of annual exceedance probabilities is now recommended because it conveys the probability, or odds, of a flood 

of a given magnitude being equaled or exceeded in any given 

year. The exceedance probability is equivalent to the reciprocal of the recurrence interval and is expressed as a percent. 

For example, a flood with an annual exceedance probability of 

1 percent corresponds to a 100-year flood. This does not imply 

that flooding will happen at regular intervals. Two streamflows 

with annual exceedance probabilities of 2 percent could occur 

in 2 consecutive years or even the same year. In contrast, a 

peakflow with an annual exceedance probability of 2 percent 

might not occur for 100 years. 

Major flooding provides a unique opportunity to assess 

and calibrate flood water-surface elevation profiles and floodplain delineations in a region. Active streamgages with long 

periods of record are the single best tool for evaluating the 

magnitude and severity of flooding events on streams. On 

streams where historical data are not available, high-water 

marks (HWMs) and hydraulic flow models allow for the 

estimation of peak streamflows and exceedance probabilities. 

Flood of April and May 2008 in Northern Maine

By Pamela J. Lombard
2 Flood of April and May 2008 in Northern Maine

Northern Maine experienced major floods in 1923, 1973, 

1974, 1979, and 1983 (Maloney and Bartlett, 1991). All these 

floods occurred in late April or early May when heavy rain 

combined with snowmelt runoff. 

Snowmelt and rainfall in northern Maine from April 28 

through April 30, 2008, resulted in floods with annual 

exceedance probabilities of equal to or less than 1 percent 

at six streamgages and annual exceedance probabilities of 

between 2 and 1 percent at three additional gages in the 

region. The State of Maine declared a state of emergency 

in Aroostook County on April 29, 2008, as a result of the 

flooding (fig. 1). On May 9, 2008, Aroostook County was 

declared a Federal disaster area qualifying it for federal 

assistance, and on May 16, the federal government expanded 

the major disaster declaration to include Penobscot County. 

Fort Kent, located on the banks of the St. John River, received 

the most damage from the flood. More than 600 people 

evacuated the region and over 100 homes were flooded. Many 

other communities in Aroostook and Penobscot Counties were 

also severely affected (figs. 1, 2). 

Antecedent Hydrologic Conditions

Areas of northern Maine received between 150 and 

200 in. of snow throughout the 2007–08 winter season—

above-average amounts for the region (River Flow Advisory 

Commission, State of Maine, 2008). From 40 to 70 in. 

of this snowpack, the equivalent of 10 to 15 in. of snow 

water, remained on the ground in mid-April in northern 

Maine. This is above-average for so late in the season 

(River Flow Advisory Commission, State of Maine, 2008). 

High temperatures caused the water content of the snow to 

drop more than 4 in. between April 15 and 22 in Fort Kent 

(fig. 3) and another 4 in. between April 22 and 29 (fig. 3), 

filling streams to capacity. In the week preceeding the 

heavy rain on April 29, the Fish River at Fort Kent (USGS 

streamgage 01013500) and the St. John River below the 

Fish River at Fort Kent (USGS streamgage 01014000) had 

streamflows with annual exceedance probabilities between 

10 and 50 percent due to snowmelt. Snowmelt caused 

the St. John River below Fish River at Fort Kent to rise 

to 104,000 ft3

/s by April 25. It then fell to 79,000 ft3/s by 

April 29 before the rain of April 29 through May 1 caused 

it to peak at 183,000 ft3

/s on May 1 (fig. 4). The Allagash 

and Penobscot Rivers also had streamflows with annual 

exceedance probabilities between 10 and 50 percent in the 

weeks leading up to the 2008 flood. 

Storm Characteristics

A low-pressure system developed in the Appalachian 

Mountain states centered around Pennsylvania on Monday, 

April 27, and the resulting storm moved into southern New 

England by April 28 and into Maine by the morning of April 

29 (Sturey and others, 2008). Heavy rain continued through 

April 30 and ranged from less than 2 to 4 in. in northern Maine 

(fig. 5). On the basis of National Weather Service precipitation 

records, the average rainfall received during the April/May 

flood of 2008 in northern Maine was roughly equivalent to a 

2-day rainfall total having an annual exceedance probability of 

10 percent (Wilks and Cember, 1993). 
Introduction 3

Figure 1. Location of study area.

EXPLANATION

Base from USGS digital data, 1:24,000

Universal Transverse Mercator projection, zone 19

Rivers

MAINE

QÚEBEC,

CANADA

NEW BRUNSWICK,

CANADA

Towns

Roads

Penobscot River

Piscataquis River

East Branch Penobscot River

Fish River

West Branch

Mattawamkeag River

St. John River

Meduxnekeag

River

Mattawamkeag River

Big Black River

Allagash River

Aroostook River

Hamlin

Van Buren

Houlton

Allagash

Fort Kent

Presque Isle

Study area

AROOSTOOK COUNTY

PISCATAQUIS COUNTY SOMERSET COUNTY

PENOBSCOT

COUNTY

WASHINGTON COUNTY HANCOCK

COUNTY

70° 69° 68° 67°

48°

47°

46°

20 MILES

0 5 10

0 5

 20 KILOMETERS

10

15

15

Maine

New

Hampshire

Vermont

Atlantic

Ocean

Qúebec,

Canada

Massachusetts

St. John River
4 Flood of April and May 2008 in Northern Maine

Figure 2. Flooding from Fish River at Soldier Pond, Maine, May 3, 2008. (Photograph by Laura Flight, 

U.S. Geological Survey)
Introduction 5

Study area

MAINE

EXPLANATION

Change in water content

in snow pack, in inches

-7

-6

-5

-4

-3

-2

Base from USGS and Maine Office of GIS digital files

Geographic Coordinate System NAD 83

DATA CONTRIBUTORS:

U.S. Geological Survey

Maine Department of Conservation

National Weather Service

Kennebec Water Power Company

A

B

MAINE

MAINE

Hamlin

Van Buren

Houlton

Allagash

Fort Kent

Hamlin

Van Buren

Houlton

Allagash

Fort Kent

Presque

Isle

Presque

Isle

40 MILES

0 10 20

0 10

 40 KILOMETERS

20

30

30

WASHINGTON

COUNTY

AROOSTOOK COUNTY

PISCATAQUIS

COUNTY

SOMERSET

COUNTY

PENOBSCOT

COUNTY

AROOSTOOK COUNTY

PISCATAQUIS

COUNTY

SOMERSET

COUNTY

PENOBSCOT

COUNTY

WASHINGTON

COUNTY

Snow-survey site

Towns

WASHINGTON

COUNTY

70° 69° 68°

47°

46°

70° 69° 68°

47°

46°

Figure 3. Change in water content in snowpack (A) from April 15 to 22, and (B) from April 22 to 29, 2008, northern Maine.
100,000

60,000

70,000

80,000

90,000

Rise due to rain

Rise due to

snowmelt

200,000

Streamflow

0.2 

1

2

10

50

04/22/2008 04/27/2008 05/02/2008 05/07/2008

DATE

STREAMFLOW, IN CUBIC FEET PER SECOND

Percent probability

 of exceedance

EXPLANATION

6 Flood of April and May 2008 in Northern Maine

Figure 4. Hydrograph of St. John River below Fish River at Fort Kent, Maine (U.S. Geological Survey streamgage 01014000), from 

April 22 through May 7, 2008, and streamflows of selected exceedance probabilities at this location.

Figure 5. Total storm precipitation from April 29 through 30, 2008, northern Maine. (Precipitation data courtesy of the 

National Weather Service)

EXPLANATION

Total precipitation, in inches

less than 2.0

2.0–2.4

2.5–2.9

3.0–3.4

3.5–4.0

Base from USGS and Maine Office of GIS digital files

Geographic Coordinate System NAD 83

40 MILES

0 10 20

0 10

 40 KILOMETERS

20

National Weather Service

Precipitation Station

Towns

30

30

Study area

MAINE

Hamlin

Van Buren

Houlton

Allagash

Fort Kent

Presque Isle

70° 69° 68°

47°

46°
Description of Flood 7

Description of Flood

Floods are typically characterized by peak water-surface 

elevations, peak streamflows, and peak streamflow exceedance 

probabilities. Peak water-surface elevations are recorded at 

streamgages and (or) estimated from HWMs at other locations 

along streams. Methods to calculate peak streamflows include 

the use of a relation between streamflow and water-surface 

elevation (a rating curve) at a streamgage or through use of 

hydraulic models at ungaged locations. 

Peak Water-Surface Elevations

Most of the streams in Aroostook and Penobscot Counties 

peaked on April 30 or May 1, 2008. Water from the St. John 

River at Fort Kent peaked at 30.17 ft (5 ft above flood stage) 

and closed international bridges in Fort Kent, Van Buren, and 

Hamlin. It also came within inches of the top of a 30-ft high 

earthen dike constructed to protect the downtown area of Fort 

Kent and hit the low steel of the International Bridge connecting Fort Kent to New Brunswick (fig. 6). 

Thirteen peak water-surface elevations from active USGS 

continuous-record streamgages in Aroostook and Penobscot 

Counties are included in this report (table 1). Peak stage 

data from streamgages typically have an accuracy of plus 

or minus 0.01 ft. In addition, a peak water-surface elevation 

was obtained from a HWM at the location of a streamgage 

discontinued in 1983, Machias River near Ashland (USGS 

streamgage 01016500). Peak water-surface elevations were 

obtained from two crest-stage streamgages at Clark Brook 

(table 1). Crest-stage streamgages are used to obtain only the 

elevation of the flood crest on a river or stream, and often are 

located both upstream and downstream of a structure. 

In addition, 63 HWMs were located and surveyed for 

elevations on streams in Aroostook and Penobscot Counties 

using the techniques of Benson and Dalrymple (1967) (table 1, 

fig. 7). HWMs typically consist of debris lines or wash lines 

caused by the flooding event and indicate the highest elevation point that water reached during the event (fig. 8). Debris 

lines usually consist of a line of fine material such as silt, 

hemlock needles, or seeds on a tree, bridge abutment, or bank; 

wash lines are defined by the absence of debris and leaves 

below them. It is important to locate, mark, and rate these 

points as soon as possible after the flooding event because 

they can quickly fade or wash away with subsequent rain. 

Figure 6. Flooding at International Bridge connecting Fort Kent, Maine, to New Brunswick, Canada, on April 30, 2008. (Photograph by 

Andrew Cloutier, U.S. Geological Survey)
8 Flood of April and May 2008 in Northern Maine

Table 1. Identification numbers and locations for high-water marks in northern Maine from flood of April and May 2008.—Continued

[HWM, high-water mark; Northings and Eastings referenced to Maine State Plane East; Datum, North American Datum of 1983; Elevations referenced to 

North American Vertical Datum of 1988; ft, feet; US, upstream; DS, downstream; LEW, left edge of water (when facing downstream); REW, right edge 

of water; USGS, U.S. Geological Survey; R., river; Rd., road; RR, railroad; Rte., route; St., street; CSG, crest-stage streamgage; WBr, West Branch; EBr, 

East Branch; all HWMs listed are approximately one structure width upstream or downstream of the listed location; eight digit site numbers refer to USGS 

streamgage numbers]

Site 

number

HWM 

number

Northing

(ft)

Easting

(ft)

Elevation 

(ft) Water body, town Location and description

01010000 1108450.3 679277.4 942.80 St. John R. at Ninemile Bridge At streamgage

01010070 1179096.7 671340.4 898.28 Big Black R. near Depot Mountain At streamgage

1 1 1258252.9 837020.1 610.71 St. John R., Dickey Rte. 161, US LEW

1 2 1256320.2 837894.3 610.05 St. John R., Dickey Rte. 161, DS REW

01010500 1257081.1 837838.9 610.09 St. John R. at Dickey At streamgage

2 3 1246082.5 847648.3 600.47 Allagash R., Allagash Rte. 161, US LEW

2 4 1246195.6 848675.8 600.41 Allagash R., Allagash Rte. 161, DS REW

01011000 1241261.3 839865.7 619.01 Allagash R. near Allagash At streamgage

3 9 1305315.7 958127.9 520.53 St. John R., Fort Kent International Bridge, US REW

3 10 1306369.6 959120.2 520.18 St. John R., Fort Kent International Bridge, DS1 REW

3 11 1306933.4 959744.3 520.15 St. John R., Fort Kent International Bridge, DS2 REW

01014000 1309427.9 960454.8 517.64 St. John R. below Fish R. at Fort Kent At streamgage

4 5 1271761.3 966087.9 573.20 Fish R., Soldier Pond Bridge Rd., US REW

4 6 1272193.1 966073.0 572.88 Fish R., Soldier Pond Bridge Rd., DS REW

5 7 1276304.0 959945.4 582.59 Wallagrass Stream, Wallagrass Rte. 11, US REW

5 8 1276290.6 960052.2 579.81 Wallagrass Stream, Wallagrass Rte. 11, DS REW

6 12 1307286.7 960945.2 519.87 Fish R., Fort Kent Blockhouse Rd., DS1 LEW

6 13 1307327.3 960760.9 516.63 Fish R., Fort Kent Blockhouse Rd., DS2 LEW

6 14 1307577.0 960684.0 519.46 Fish R., Fort Kent Blockhouse Rd., DS3 LEW

6 15 1306963.5 961089.6 520.04 Fish R., Fort Kent Rte. 1, US LEW

7 16 1303766.3 964324.6 521.67 Fish R., Fort Kent Jalbert Park, US REW

7 17 1304409.5 964242.6 521.72 Fish R., Fort Kent Jalbert Park, DS LEW

01013500 1301927.3 963688.5 524.60 Fish R. near Fort Kent At streamgage

8 18 1346149.0 1027437.7 468.89 St. John R., Madawaska International Bridge, DS REW

9 19 1343925.3 1034418.7 489.45 Factory Brook, Madawaska Rte. 1, US LEW

10 20 1273891.2 1125227.4 450.23 St. John R., Van Buren International Bridge, US REW

10 21 1273555.6 1125392.9 449.92 St. John R., Van Buren International Bridge, DS REW

11 22 1010439.6 1008291.8 640.51 Houlton Brook, T9R5 WELS Oxbow Rd., US LEW

11 23 1010429.5 1008246.3 640.33 Houlton Brook, T9R5 WELS Oxbow Rd., US REW

11 24 1010317.0 1008215.7 637.33 Houlton Brook, T9R5 WELS Oxbow Rd., DS REW

12 25 1041326.2 1016334.3 548.09 Aroostook R., Masardis Garfield Rd., US LEW

12 26 1041668.6 1016057.8 552.94 Aroostook R., Masardis Garfield Rd., DS LEW

01015800 1041392.7 1016553.2 548.13 Aroostook R. near Masardis At streamgage

13 27 1079558.9 1000670.4 542.67 Machias R., Ashland Garfield Rd., US discontinued streamgage, REW

13 28 1079542.5 1000706.9 542.65 Machias R., Ashland Garfield Rd., DS discontinued streamgage, REW

01016500 1079756.7 1000632.1 542.48 Machias R. near Ashland At streamgage

14 29 1081006.1 1004286.7 537.03 Aroostook R., Ashland Rte. 11, US LEW

14 30 1081205.7 1004860.1 536.26 Aroostook R., Ashland Rte. 11, DS REW

15 31 1139272.7 1069872.9 469.95 Salmon Brook, Washburn Bridge St./Hines St., US LEW

15 32 1139167.5 1069783.0 468.85 Salmon Brook, Washburn Bridge St./Hines St., DS LEW

16 33 1133107.7 1070010.0 451.07 Aroostook R., Washburn RR Bridge, US REW

16 34 1133952.0 1070438.8 448.96 Aroostook R., Washburn Castle Hill Rd., US REW (DS of RR)
Description of Flood 9

Table 1. Identification numbers and locations for high-water marks in northern Maine from flood of April and May 2008.—Continued

[HWM, high-water mark; Northings and Eastings referenced to Maine State Plane East; Datum, North American Datum of 1983; Elevations referenced to 

North American Vertical Datum of 1988; ft, feet; US, upstream; DS, downstream; LEW, left edge of water (when facing downstream); REW, right edge 

of water; USGS, U.S. Geological Survey; R., river; Rd., road; RR, railroad; Rte., route; St., street; CSG, crest-stage streamgage; WBr, West Branch; EBr, 

East Branch; all HWMs listed are approximately one structure width upstream or downstream of the listed location; eight digit site numbers refer to USGS 

streamgage numbers]

Site 

number

HWM 

number

Northing

(ft)

Easting

(ft)

Elevation 

(ft) Water body, town Location and description

16 35 1133322.7 1070797.4 448.25 Aroostook R., Washburn Castle Hill Rd., DS REW

01017000 1134241.7 1070128.6 449.70 Aroostook R. at Washburn At streamgage

17 36 1108426.3 1106971.0 426.42 Aroostook R., Presque Isle Rte. 1, US LEW

17 37 1107575.7 1108104.2 425.71 Aroostook R., Presque Isle Rte. 1, DS LEW

18 38 1159623.3 1108949.2 398.48 Aroostook R., Caribou Above Dam LEW

18 39 1161929.8 1108430.2 392.06 Aroostook R., Caribou Rte. 161 US LEW

18 40 1163048.2 1108496.2 389.27 Aroostook R., Caribou Rte. 161 DS LEW

19 41 1175374.1 1121968.8 415.96 Little Madawaska R., Caribou Rte. 89 US REW

20 42 1164034.0 1124958.9 390.99 Nichols Brook, Caribou Grimes Mill Rd., US LEW

20 43 1164118.9 1124801.7 383.43 Nichols Brook, Caribou Grimes Mill Rd., DS REW

21 44 1133963.5 1151269.6 361.43 Aroostook R., Fort Fairfield Rte. 1A, US LEW

21 45 1133425.7 1152065.6 360.28 Aroostook R., Fort Fairfield Rte. 1A, DS LEW

22 46 913292.3 1024534.8 636.06 WBr Mattawamkeag R., Moro Plantation Rte. 11, US REW

22 47 913148.7 1024659.4 634.02 WBr Mattawamkeag R., Moro Plantation Rte. 11, DS REW

23 48 856246.7 1039509.8 454.81 WBr Mattawamkeag R., Island Falls RR Bridge, DS1 REW

23 49 856255.2 1039503.0 455.15 WBr Mattawamkeag R., Island Falls RR Bridge, DS2 REW

23 50 856300.5 1039525.9 455.73 WBr Mattawamkeag R., Island Falls RR Bridge, DS3 REW

23 51 856296.6 1039524.0 455.90 WBr Mattawamkeag R., Island Falls RR Bridge, DS4 REW

23 52 856497.0 1039249.8 457.26 WBr Mattawamkeag R., Island Falls RR Bridge, US1 REW

23 53 856495.0 1039253.1 457.20 WBr Mattawamkeag R., Island Falls RR Bridge, US2 REW

23 54 856617.2 1039213.0 457.15 WBr Mattawamkeag R., Island Falls RR Bridge, US3 REW

24 55 855030.9 1041258.5 456.70 WBr Mattawamkeag R., Island Falls Bog Bk Rd., US LEW

24 56 855099.4 1041105.2 454.27 WBr Mattawamkeag R., Island Falls Bog Bk Rd., DS1 LEW

24 57 855106.9 1041098.0 454.85 WBr Mattawamkeag R., Island Falls Bog Bk Rd., DS2 LEW

25 58 903925.9 1095238.7 608.55 Marley Brook, Smyrna Rte. 2, US1 REW

25 59 903906.5 1095246.5 607.73 Marley Brook, Smyrna Rte. 2, US2 REW

27 60 710278.7 974185.1 247.56 EBr Penobscot R., Medway Rte. 157/11 US REW

27 61 709304.5 974616.6 246.88 EBr Penobscot R., Medway Rte. 157/11 DS REW

26 62 753105.1 961631.3 310.21 EBr Penobscot R., Grindstone Rte. 11, US of RR (US of USGS gage) LEW

26 63 751852.2 961678.4 309.12 EBr Penobscot R., Grindstone Rte. 11, DS of RR (at USGS gage) LEW

01029500 752300.3 961410.3 309.41 EBr Penobscot R. at Grindstone At streamgage

01018000 889561.2 1144887.1 341.11 Meduxnekeag R. near Houlton At streamgage

01031500 550894.1 774158.5 371.41 Piscataquis R. near Dover-Foxcroft At streamgage

01034000 581243.6 889339.1 261.39 Piscataquis R. at Medford At streamgage

01034500 572151.2 945253.3 146.89 Penobscot R. at West Enfield At streamgage

01012895 1253301.8 961700.1 637.20 Clark Brook At US CSG 

01012895 1253301.8 961700.1 632.77 Clark Brook At DS CSG 
10 Flood of April and May 2008 in Northern Maine

Figure 7. Site numbers of surveyed high-water marks following the April and May 2008 flood in northern Maine. (See table 1 for 

high-water mark numbers)

Base from USGS digital data, 1:24,000

Universal Transverse Mercator projection, zone 19

20 MILES

0 5 10

0 5

 20 KILOMETERS

10

15

15

MAINE

QÚEBEC,

CANADA

NEW BRUNSWICK,

CANADA

Hamlin

Van Buren

Houlton

Allagash

Fort Kent

Presque

Isle

Penobscot River

Piscataquis River

East Branch Penobscot River

Fish River

West Branch

Mattawamkeag River

St. John River

Meduxnekeag

River Mattawamkeag River

Big Black River

Allagash River

Aroostook River AROOSTOOK COUNTY

PISCATAQUIS COUNTY SOMERSET COUNTY

PENOBSCOT

COUNTY

WASHINGTON COUNTY HANCOCK

COUNTY

70° 69° 68° 67°

48°

47°

46°

Maine

New

Hampshire

Vermont

Atlantic

Ocean

Qúebec,

Canada

Massachusetts

7 Site and

identifier

EXPLANATION

Rivers

Towns

Roads

8 9

7

6

3

5

4 2 1

26

27

25

24

23

22

21

20

19

18

17

16

15

13 14

12

11

10

St. John River
Description of Flood 11

Figure 8. High-water mark identification and marking after the April/May 2008 flood in northern Maine: (A) debris line, (B) debris line 

along St. John River dike in Fort Kent looking downstream at International Bridge, (C) debris line on tree, (D) U.S. Geological Survey 

high-water marker, (E) setting high-water mark along St. John River in Allagash, and (F) debris line on fence in Fort Kent. (Photographs 

by Laura Flight and Andrew Cloutier, U.S. Geological Survey)

A B C

D E

F
12 Flood of April and May 2008 in Northern Maine

HWMs are rated on the basis of the type and quality of the 

debris line or wash line and corroborating evidence in the 

area. All HWMs used in this analysis were marks with an 

estimated accuracy of within 0.2 ft of the true peak watersurface elevation during the event. The dates that the peak 

water-surface elevations occurred at the 63 HWM locations 

are unknown.

All HWMs included in this report were surveyed 

relative to local reference points. The elevations of the local 

reference points were established with high precision Global 

Positioning System (GPS) instrumentation and referenced to 

NAVD 88. 

Peak Streamflows

Peak streamflows associated with the April/May 2008 

flood were obtained at 20 sites on 15 streams (table 2, fig. 9). 

Peak streamflows were determined through rating curves (the 

relation between streamflow and water-surface elevations) 

at 14 long-term continuous-record streamgages (1 of which 

is currently no longer in operation) and through indirect 

hydraulic models at 6 sites including 1 active crest-stage 

gage, 4 discontinued crest-stage gages, and 1 ungaged site 

on Route 11 in Moro Plantation that was the location of a 

bridge failure during the 2008 flood. The April/May 2008 peak 

streamflow was the highest recorded peak streamflow at seven 

streamgages on five streams. These included Big Black River 

near Depot Mountain; St. John River at Dickey and below 

Fish River at Fort Kent; Allagash River near Allagash; Fish 

River near Fort Kent; and Aroostook River at Masardis and at 

Washburn—streamgages having periods of record from 25 to 

84 years (table 2, fig. 9).

The most reliable method with which to calculate peak 

streamflows is a calibrated and recently confirmed rating curve 

at a streamgage. To compute the peak streamflow with a rating 

curve, available streamflow measurements and corresponding 

stream water-surface elevations at a site are analyzed, plotted, graphically represented as a line, and extrapolated beyond 

the calibrated range of measured streamflows when plotted 

in logarithmic space (Rantz and others, 1982). Rating-curve 

development and extension depend on the type and stability 

of the river control at high flows. Historic rating curves can be 

used at sites that are no longer gaged if the site is presumed to 

have a stable rating curve. 

If a rating curve is not available or is unreliable for 

extremely high flows, the peak flow can be calculated using 

indirect methods. Indirect methods of determining peak 

flow are based on hydraulic relations between flow and the 

geometry of the channel (Benson and Dalrymple, 1967; 

Matthai, 1967). For this study, the geometry of the channel and bridge and estimates of downstream slope and 

roughness values were defined through field surveys and 

entered into the one-dimensional steady-flow water-surface 

profile computation component of the U.S. Army Corps 

of Engineers step-backwater computer model HEC-RAS 

(U.S. Army Corps of Engineers, 2004). Flows were selected 

and input into the models, and the models were calibrated so 

that the resulting locations and water-surface elevation output 

from HEC-RAS matched the locations and elevations of 

HWMs observed in the field (table 1). 

Exceedance Probabilities of Peak Streamflows

Peak streamflows from the April/May 2008 flood were 

compared to statistical peak streamflows with standard annual 

exceedance probabilities at the same locations in northern 

Maine to determine the exceedance probabilities of the April/

May 2008 peak streamflows (table 2, fig. 10). All estimates of 

exceedance probability have uncertainty associated with them, 

and the uncertainty generally increases as the exceedance 

probability decreases, especially at sites where the period of 

record is short. 

Peak flows with exceedance probabilities of 10-, 2-, 

1-, and 0.2-percent for streamgages with at least 10 years 

of peak-flow data were calculated using the guidelines 

(Bulletin 17B) of the Interagency Advisory Committee on 

Water Data (1982) as applied for Maine in Hodgkins (1999). 

Although Hodgkins (1999) provides equations for calculating 

recurrence intervals, the annual exceedance probability is the 

reciprocal of the recurrence interval. For the 14 streamgages 

with sufficient annual peak data, a Pearson Type III probability 

distribution was fitted to the logarithms (base 10) of the 

observed annual peak flows at a given streamgage. Weighted 

estimates of 10-, 50-, 100-, and 500-year peak flows from 

Hodgkins (1999) were updated with an additional 9 years of 

data where available for streamgages in northern Maine and 

then converted to 10-, 2-, 1-, and 0.2-percent exceedance 

probabilities for this report (table 2). 

For the six locations where flows were determined by 

indirect methods, historical streamflow records were not 

available. Annual exceedance probabilities for peak flows 

at sites without historical peak-flow data were calculated 

using the regression equations presented in Hodgkins (1999). 

Regression equations were developed using generalized least 

squares regression procedures that were based on data from 

70 USGS streamgages in Maine and eastern New Hampshire. 

The explanatory variables used in the equations were drainage 

area and percentage of wetlands in the basin.

Streamflows observed during the April/May 2008 flood 

had the lowest probabilities of exceedance from Allagash to 

Fort Kent on the border with Canada (fig. 10). The Allagash 

River near Allagash, St. John River in Fort Kent, and Fish 

River at Fort Kent all had flows with annual exceedance 

probabilities less than 1 percent. Although the East Branch 

of the Penobscot River at Grindstone (USGS station number 

01029500, fig. 9) had a streamflow with an annual probability 

of exceedance of less than 1 percent, this site is regulated. 
Description of Flood

13

Table 2. Peak flows for selected exceedance probabilities and actual peak flows calculated for the April and May 2008 flood in northern Maine.[USGS, U.S. Geological Survey; mi2, square miles; ft3/s, cubic feet per second; Annual exceedance probability is the chance of a flood of a given magnitude being equaled or exceeded in any given year, and 

is equivalent to the reciprocal of the recurrence interval. R., river; EBr, East Branch; WBr, West Branch; NA, not applicable; ft, feet; Rd., road; Rte., route; <, less than; >, greater than]

USGS 

station 

number

Stream and location Road crossing Drainage area (mi2) Percentage of wetlands in basin

Peak flows 

(ft3/s) Peak 

stage 

NAVD 88

(ft)

April–May 

2008 Annual exceedance 

probability

(percent)

Period 

of 

record

(yrs)

Annual exceedance probability

(percent) Peak flow (ft3/s)

10 2 1 0.20

Calculated with flood-frequency analyses

Computed 

with rating 

curves

01010000 St. John R. at Ninemile Bridge 1,341 NA 36,400 45,400 48,900 56,800 942.80 43,600 10–2 158

01010070 Big Black R. near Depot Mountain 171 NA 7,550 10,000 11,000 13,400 898.28 7,420 >10 25

01010500 St. John R. at Dickey 2,680 NA 77,700 99,800 109,000 130,000 610.09 104,000 2–1 162

01011000 Allagash R. near Allagash 1,478 NA 24,700 33,300 36,900 45,600 619.01 40,900 1–0.2 77

01013500 Fish R. near Fort Kent 873 NA 12,000 15,000 16,300 19,300 524.60 18,300 1–0.2 84

01014000 St. John R. below Fish R. at Fort Kent 5,914 NA 121,000 152,000 164,000 193,000 517.64 183,000 1–0.2 182

01015800 Aroostook R. near Masardis 892 NA 21,000 26,800 29,100 34,500 548.13 29,500 1 51

01016500 Machias R. near Ashland2 330 NA 10,500 14,700 16,500 21,100 542.48 9,730 >10 32

01017000 Aroostook R. at Washburn 1,654 NA 36,100 46,200 50,400 59,900 449.70 49,500 2–1 78

01018000 Meduxnekeag R. near Houlton 175 NA 5,620 7,620 8,480 10,500 341.11 4,370 >10 47

01029500 EBr Penobscot R. at Grindstone3 837 NA 23,000 31,200 34,800 43,200 309.41 35,200 1–0.2 89

01031500 Piscataquis R. near Dover-Foxcroft 298 NA 15,600 22,700 25,800 33,700 371.41 15,200 >10 106

01034000 Piscataquis R. at Medford 1,162 NA 39,100 56,000 63,700 82,600 261.39 43,200 10–2 178

01034500 Penobscot R. at West Enfield3 6,422 NA 100,000 133,000 147,000 180,000 146.89 126,000 10–2 1107

Calculated with regression equations

Computed 

with indirect 

methods

422 WBr Mattawamkeag R., Island Falls Bog Brook Rd. 44.6 4.44 2,183 3,196 3,667 4,820 636.06 3,680 1 None

501015700 Houlton Brook, T9R5 WELS Oxbow Rd. 6.09 1.35 189 275 316 413 640.42 302 2–1 10

501014700 Factory Brook, Madawaska Rte. 1 6.01 0.12 752 1,203 1,420 1,982 489.45 332 >10 10

501017300 Nichols Brook, Caribou Grimes Mill 3.81 0.27 365 577 680 940 391.00 193 >10 10

501017900 Marley Brook, Smyrna Rte. 2 1.49 0.02 261 434 520 745 608.56 203 >10 18

01012895 Clark Brook, Wallagrass Rte. 11 1.12 0.11 114 183 218 305 637.20 669 >10 8

1 Does not include additional historical period that is outside period of continuous record.2 This station was discontinued; thus rating is from 1983. No evidence that 2008 flow was not exceeded between 1984–2007. 3 These stations affected by regulation, and thus exceedance probability estimates only apply if regulation continues as was done historically.4 This location was never a U.S. Geological Survey streamgage, but peak streamflow elevations and flows were calculated because this was the location of a bridge failure. 

Station number refers to location on figure 9.

5 Although these stations were run as crest-stage gages from 1964–1974, these records were not used in computing the flow frequencies due to altered conditions of structures.6 This peak flow computed with rating curve from crest-stage streamgage run from 2000 to 2009.
14 Flood of April and May 2008 in Northern Maine

Figure 9. Sites where peak streamflows were calculated for the April and May 2008 flood in northern Maine.

MAINE

QÚEBEC,

CANADA

NEW BRUNSWICK,

CANADA

Penobscot River

Piscataquis River

East Branch Penobscot River

Fish River

West Branch

Mattawamkeag River

St. John River

St. John River

Meduxnekeag

River

Mattawamkeag River

Big Black River

Allagash River

Aroostook River

Hamlin

Van Buren

Houlton

Allagash

Fort Kent

Presque Isle AROOSTOOK COUNTY

PISCATAQUIS COUNTY SOMERSET COUNTY

PENOBSCOT

COUNTY

WASHINGTON COUNTY HANCOCK

COUNTY

70° 69° 68° 67°

48°

47°

46°

Maine

New

Hampshire

Vermont

Atlantic

Ocean

Qúebec,

Canada

Massachusetts

01010500

01010070

22

01034500

01034000

01031500

01029500

01018000

01017300

01017000

01016500

01015800

01015700

01013500

01011000

01014700

01010070

01010000

01010000

01017900

01012895 01010500

01014000

Site and identifier

EXPLANATION

Rivers

Towns

Roads

Base from USGS digital data, 1:24,000

Universal Transverse Mercator projection, zone 19

20 MILES

0 5 10

0 5

 20 KILOMETERS

10

15

15
Description of Flood 15

EXPLANATION

Rivers

MAINE

QÚEBEC,

CANADA

NEW BRUNSWICK,

CANADA

Base from USGS digital data, 1:24,000

Universal Transverse Mercator projection, zone 19

20 MILES

0 5 10

0 5

 20 KILOMETERS

10

15

15

AROOSTOOK COUNTY

PISCATAQUIS COUNTY SOMERSET COUNTY

PENOBSCOT

COUNTY

WASHINGTON COUNTY HANCOCK

COUNTY

70° 69° 68° 67°

48°

47°

46°

1

1

>10

>10

>10

>10

2–1

>10

2–1

>10

>10

2–1

>10

10−2

10–2

10–2

10–2

1–0.2

1–0.2

1–0.2

1–0.2

Annual exceedance

probability,

in percentage

and identifier

Maine

New

Hampshire

Vermont

Atlantic

Ocean

Qúebec,

Canada

Massachusetts

Roads

Hamlin

Van Buren

Houlton

Allagash

Fort Kent

Presque Isle

Penobscot River

Piscataquis River

East Branch Penobscot River

Fish River

West Branch

Mattawamkeag River

St. John River

Meduxnekeag

River

Big Black River

Allagash River

Aroostook River

St. John River

Figure 10. Annual probability of exceedance for peak streamflows observed during the April and May 2008 flood at selected 

sites in northern Maine.
16 Flood of April and May 2008 in Northern Maine

Comparison of 2008 Flood Data to 

Published Flood Insurance Studies

Standard exceedance probabilities for streamflows 

calculated in this report (table 2) were compared to the peak 

streamflow recurrence intervals published in the effective 

flood insurance studies (FIS) for each of the five sites 

where information from a detailed FIS is available (table 3). 

Applicable FISs were published from 1979 to 2003 (Federal 

Emergency Management Agency, various dates). Differences 

between exceedance probabilities in this flood report and the 

reciprocals of the recurrence intervals in the effective FISs 

resulted in different estimates of the exceedance probability 

for the 2008 flood only at the two sites on the Aroostook 

River. Aroostook River at Washburn had a 2008 peak flow 

of 49,500 ft3

/s, giving it an annual exceedance probability 

between 2 and 1 percent (table 2)—equivalent to a recurrence 

interval between 50 and 100 years. A peak flow of 49,500 ft3

/s 

would have had a recurrence interval between 10 and 50 years 

in the Washburn FIS (Federal Emergency Management 

Agency, 1980) (table 3). Aroostook River near Masardis 

had a 2008 peak flow of 29,500 ft3

/s, giving it an annual 

exceedance probability of 1 percent (table 2)—equivalent to 

a recurrence interval of 100 years. A peak flow of 29,500 ft3

/s 

would have had a recurrence interval less than 100 years in 

the Masardis FIS (Federal Emergency Management Agency, 

1988) (table 3). Exceedance probabilities for this report and 

the recurrence intervals in the effective FISs were calculated 

using Log Pearson type III frequency analyses at continuousrecord streamgages. Thus, differences show where 30 years of 

additional data can change statistical flows over time. 

In a separate analysis, the peak water-surface elevations 

observed in the April/May 2008 flood were compared to the 

peak water-surface elevations that would have been expected 

if the April/May 2008 peak streamflows were applied to the 

recurrence-interval data and the elevation profiles from the 

effective FIS for the given location. Discrepancies were found 

at two sites. A peak water-surface elevation of 524.60 ft was 

observed at Fish River near Fort Kent in 2008. The 2008 

peak flow of 18,300 ft3

/s would have had a peak watersurface elevation of 520.8 ft if applied to the Fort Kent FIS 

(Federal Emergency Management Agency, 1979) (table 3). 

A peak water-surface elevation of 517.64 ft was observed at 

St. John River at Fort Kent in 2008. The 2008 peak flow of 

183,000 ft3

/s would have had a peak water-surface elevation 

of 519.0 ft if applied to the Fort Kent FIS (table 3). The 

discrepancies are likely because hydraulic models from which 

FIS elevations were obtained were not calibrated to a flood 

the magnitude of which was observed in 2008 (table 3). In 

addition, there are differences in the hydraulic models (i.e., 

improved bridge routines in HEC-RAS compared to HEC-2) 

and (or) differences in modeler input parameters (roughness 

coefficients, etc.). At both streamgages with discrepancies, the 

2008 flood was the flood of record. Additional years of data, 

including the April/May 2008 flood, will allow for more accurate calibration of future hydraulic models in this region. FIS 

profiles were adjusted from NGVD 29 to NAVD 88 in order to 

make the comparison with 2008 peak water-surface elevations 

surveyed in NAVD 88. 

Table 3. Relation of computed April and May 2008 peak streamflows and high-water mark elevations to flood-insurance study data at 

selected streamgages in northern Maine.

[All streamflow recurrence intervals from flood insurance studies (FIS) computed with Log-Pearson type-3 frequency analyses; all elevations are in NAVD 

88; FIS profile elevations were originally in NGVD 29, but were adjusted to NAVD 88 for this report; USGS, U.S. Geological Survey; ft3/s, cubic feet per 

second; yr, year; ft, feet; R., river; --, data not available; 10-, 50-, 100-, and 500-yr recurrence intervals correspond to 10-, 2-, 1-, and 0.2 percent annual 

exceedance probabilities]

USGS

station 

number

Water body and 

location

2008 

Peak flow 

(ft3

/s)

Streamflow recurrence intervals from 

flood insurance studies

(ft3

/s)

2008 

Elevation 

(ft)

Elevations from FIS profiles

(ft)

10-yr 50-yr 100-yr 500-yr 10-yr 50-yr 100-yr 500-yr

01010500 St. John R. at Dickey 104,000 -- -- 107,900 -- 610.09 -- -- 624.508 --

01013500 Fish R. near Fort Kent 18,300 12,300 16,300 18,000 22,200 524.60 518.626 520.026 520.826 522.226

01014000 St. John R. below Fish R. 

at Fort Kent

183,000 121,000 158,000 175,000 210,000 517.64 513.506 517.306 518.406 521.006

01015800 Aroostook R. near 

Masardis

29,500 -- -- 29,600 -- 548.13 -- -- 549.059 --

01017000 Aroostook R. at 

Washburn

49,500 37,675 49,885 55,000 68,200 449.70 447.596 449.996 450.596 452.796
References Cited 17

Summary and Conclusions

Above average snowpacks late into the second week in 

April 2008, rapid snowmelt during the third week in April, 

and a low-pressure system dropping from two to four in. of 

rain in northern Maine from April 29–30, 2008, resulted in 

record-high peak water-surface elevations and peak streamflows in northern Aroostook County on April 30 and May 1, 

2008. The most severe flooding was in Fort Kent. Peak watersurface elevations resulting from the flood were obtained at 

13 continuous-record streamgages and 63 surveyed high-water 

marks on streams in Aroostook and Penobscot Counties.

Peak streamflows for the April/May 2008 flood were 

computed at 20 sites on 15 streams through water-surface 

elevation/streamflow rating curves or hydraulic flow models. 

Seven long-term streamgages having 25 to 84 years of record 

on the Big Black, St. John, Allagash, Fish, and Aroostook 

Rivers recorded maximum streamflows for their respective 

periods of record. Streamflows with exceedance probabilities 

equal to or less than 1 percent were recorded on the St. John 

and Fish Rivers in Fort Kent, the Allagash River in Allagash, 

the Aroostook River near Masardis, and the West Branch Mattawamkeag River at Moro Plantation. The St. John River at 

Dickey, the Aroostook River at Washburn, and Houlton Brook 

at T9R5WELS all had streamflows with exceedance probabilities between 1 and 2 percent. 

Minimal differences between peak flows of standard 

annual exceedance probabilities in this flood report and peak 

flows of equivalent recurrence intervals at the same locations 

in the effective Federal Emergency Management Agency flood 

insurance studies at five locations in Aroostook County were 

likely because of Log Pearson type III frequency analyses 

being used in both cases at the same long-term continuousrecord streamgages. Differences on the Aroostook River at 

Washburn and at Masardis show that 30 years of additional 

data can result in improvements to statistical flows over time. 

Discrepancies between peak water-surface elevations in the 

flood insurance studies and peak water-surface elevations 

observed in 2008, given the flow observed in the April/May 

2008 flood at Fish River near Fort Kent and St. John River 

below Fish River at Fort Kent, are likely due to differences in 

hydraulic models; in addition, flood insurance studies-derived 

elevations had not previously been calibrated to a flood of the 

magnitude observed in 2008. 

Acknowledgments

The author thanks Thomas Hawley from the National 

Weather Service for providing meteorological data for this 

report. The following USGS employees provided substantial 

assistance by collecting the field data for this report: Lance 

Chapman, Laura Flight, Andrew Cloutier, Mark Huard, and 

Garrett Luszcski. 

References Cited

Benson, M.A., and Dalrymple, Tate, 1967, General field and 

office procedures for indirect discharge measurements: 

U.S. Geological Survey Techniques of Water-Resources 

Investigations, book 3, chap. A1, 30 p.

Federal Emergency Management Agency, 1979–2003, Flood 

insurance studies, Towns of Allagash, Fort Kent, Masardis, 

and Washburn, Maine: Washington, D.C., various dates.

Hodgkins, G.A., 1999, Estimating the magnitude of peak 

flows for streams in Maine for selected recurrence intervals: 

U.S. Geological Survey Water-Resources Investigations 

Report 99–4008, 45 p.

Interagency Advisory Committee on Water Data, 1982, 

Guidelines for determining flood flow frequency: 

Water Resources Council Bulletin 17B, 28 p.

Maloney, T.J., and Bartlett, W.P., Jr., 1991, Maine floods 

and droughts, in Paulson, R.W., Chase, E.B., Roberts, 

R.S., and Moody, D.W., comps., National water summary 

1988–99—Hydrologic events and floods and droughts: 

U.S. Geological Survey Water Supply Paper 2375, 591 p.

Matthai, H.F., 1967, Measurement of peak discharge at width 

contractions by indirect methods: U.S. Geological Survey 

Techniques of Water-Resources Investigations, book 3, 

chap. A4, 44 p.

Rantz, S.E., and others, 1982, Measurement and computation 

of streamflow: U.S. Geological Survey Water-Supply Paper 

2175, v 2., 631 p.

River Flow Advisory Commission, State of Maine, 2008, 

Maine cooperative snow survey: accessed August 1, 2008, 

at http://www.maine.gov/rfac/rfac_snow.shtml.

Sturey, A., Turner, M., Jensenius, J., and Hawley, T., 2008, 

General overview of April/May flooding in Maine 2008: 

National Weather Service, Caribou and Gray, Maine, 14 p.

U.S. Army Corps of Engineers, 2008, HEC-RAS River 

Analysis System Version 4.0 March 2008: Davis, Calif., 

Hydrologic Engineering Center, accessed November 2008 

at http://www.hec.usace.army.mil/.

Wilks, D.S., and Cember, R.P., 1993, Atlas of precipitation 

extremes for the northeastern United States and 

southeastern Canada: Ithaca, N.Y., Cornell University, 

Northeast Regional Climate Center Research publication 

RR 93-5, 40 p.
Prepared by the Pembroke Publishing Service Center.

For more information concerning this report, contact:

Director

U.S. Geological Survey

Maine Water Science Center

196 Whitten Road

Augusta, ME 04330

dc_me@usgs.gov

or visit our Web site at:

http://me.water.usgs.gov
 Lombard, P.J.—Flood of April and May 2008 in Northern Maine—Scientific Investigations Report 2010–5003