U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2013–3065

August 2013

Prepared in cooperation with the Northeast Texas Municipal Water District and the Texas Commission on Environmental Quality

Baseline Assessment of Physical Characteristics, Aquatic Biota, and Selected 

Water-Quality Properties at the Reach and Mesohabitat Scale for Three 

Stream Reaches in the Big Cypress Basin, Northeastern Texas, 2010–11

To help sustain aquatic biota, environmental flows 

are increasingly being established (prescribed) for 

streams throughout the United States. Environmental 

flows are agreed upon streamflows established to 

sustain aquatic biota and other organisms that rely on a 

healthy riverine ecosystem, and these streamflows often 

vary on a seasonal basis. In the Big Cypress Basin in 

Texas, environmental flows are prescribed as part of the 

Sustainable Rivers Project (SRP), a partnership between 

the U.S. Army Corps of Engineers (USACE) and the 

Nature Conservancy with input and oversight provided 

by the Texas Commission on Environmental Quality. 

Implementation details are handled at the local level. For 

example, the USACE and Northeast Texas Municipal 

Water District are working together to determine the best 

strategy to implement prescribed environmental flows 

for Big Cypress Bayou downstream from the Lake O’ the 

Pines, which is managed by USACE (fig. 1). The goal of 

the SRP is to alter existing operations at USACE dams in 

order to enhance habitat conditions for animals and plants 

that depend on flows downstream from the dams by 

returning flows to a more natural flow regime. The SRP 

is active in eight river basins across the United States, 

including Big Cypress Bayou (Konrad, 2010). 

The U.S. Geological Survey (USGS), in cooperation 

with the Northeast Texas Municipal Water District and 

the Texas Commission on Environmental Quality, did a 

baseline assessment in 2010–11 of physical characteristics 

and selected aquatic biota (fish and mussels) collected 

at the mesohabitat scale for three stream reaches in 

Printed on recycled paper

EXPLANATION

Watershed of Big Cypress Basin

 Big Cypress Creek and Bayou

 Black Cypress Creek and Bayou

 Little Cypress Creek and Bayou

 Caddo Lake

Boundary of Big Cypress Basin in Texas

Study reach with U.S. Geological Survey station

 number—Short name in parentheses

U.S. Geological Survey streamflow-gaging 

 station and station number

07346071

(Little Cypress)

07346000

Gulf of

Mexico

TEXAS

Study

area

Caddo

 Lake

Lake O’ 

 the Pines

Black

 Cypress

 Bayou

Little Cypress

Bayou

Big Cypress

 Bayou

Little Cypress

Creek

Big Cypress

Creek

Black Cypress Creek TEXAS LOUISIANA

ARKANSAS

Area enlarged

0 10 20 MILES

0 10 20 KILOMETERS

94°30'

95°00'

95°30'

33°00'

32°30'

93°30'

94°00'

Jefferson

Lake O’

the

Pines

Big Cypress Bayou

Black Cypress Bayou

Little Cypress Bayou

French Creek

MARION COUNTY

HARRISON COUNTY

07346000

07346045

07346070

07346044

(Black Cypress)

07346015

(Big Cypress 02)

07346017

(Big Cypress 01)

07346071

(Little Cypress)

07346044

(Black Cypress)

07346015

(Big Cypress 02)

07346017

(Big Cypress 01)

07346071

(Little Cypress)

Base modified from U.S. Geological Survey

1:24,000 quadrangle digital data

Universal Transverse Mercator projection, zone 15 

North American Datum of 1983

0 1 2 MILES

0 1 2 KILOMETERS

94°20’

32°40’

32°45’

32°50’ 94°30’ 94°25’ 94°15’

Figure 1. Location of study area, Big Cypress Basin, northeastern Texas.
U.S. Geological Survey scientists assembling cataraft for collecting 

fish from Big Cypress Creek, Texas, July 27, 2011. Photograph taken 

by Erin C. Sewell, U.S. Geological Survey.

U.S. Geological Survey scientists collecting fish from Big Cypress 

Creek, Texas, July 27, 2011. Photograph taken by Justin A. McInnis, 

U.S. Geological Survey.

the Big Cypress Basin in northeastern Texas for which 

environmental flows have been prescribed. Mesohabitats 

are visually distinct units of habitat within the stream 

(Pardo and Armitage, 1997) with unique depth, velocity, 

slope, substrate, and cover. Mesohabitats in reaches of Big 

Cypress, Black Cypress, and Little Cypress Bayous (fig. 

1) were evaluated to gain an understanding of how fish 

communities and mussel populations varied by habitat. 

Selected water-quality properties were also measured in 

isolated pools in Black Cypress and Little Cypress. All 

of the data were collected in the context of the prescribed 

environmental flows. The information acquired during the 

study will support the long-term monitoring of biota in 

relation to the prescribed environmental flows (table 1). 

Biological and physical characteristic data were 

collected during a period of low flow in July–August 

2010 and a period of very low flow in July 2011 from two 

sites on Big Cypress Bayou, and one site on both Black 

Cypress Bayou and Little Cypress Bayou. The upstream 

reach of Big Cypress Bayou is referred to as the Big 

Cypress 02 site. The downstream site on Big Cypress 

Bayou is referred to as the Big Cypress 01 site and was 

sampled exclusively for mussels (fig. 1).

Differences in physical characteristics such as stream 

width and depth can affect the abundance and variety of 

the fish and mussels in a stream. The widths and depths 

of the stream varied appreciably where physical habitat 

data were collected in 2010. The reach at the Big Cypress 

02 site was the widest and deepest, with a mean width of 

62.2 feet (ft) and a mean depth of 5.5 ft in main-channel 

mesohabitats. The reach at the Black Cypress site was the 

narrowest of the three reaches, with a mean width of 29.1 ft 

and a mean depth of 3.3 ft in main-channel mesohabitats. 

Table 1. Prescribed environmental flows (in cubic feet per second) for Big Cypress Bayou, Black Cypress Bayou, and Little Cypress Bayou 

based upon a variety of ecological objectives during dry and average years (Caddo Lake Institute, 2010). 

Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec.

Dry year Fish habitat Spawning habitat Maintain aquatic diversity Fish habitat

Big Cypress Bayou 90 90 218 198 114 49 13 6 6 40 90 90

Black Cypress Bayou 125 201 242 140 80 42 11 4 4 4 19 91

Little Cypress Bayou 112 186 219 158 86 38 12 5 5 5 18 68

Average year Fish habitat Benthic drift and dispersal, fish spawning Fish habitat Fish habitat

Big Cypress Bayou 268 347 390 330 150 79 35 40 40 40 90 117

Black Cypress Bayou 222 300 306 205 156 95 32 5 4 13 74 209

Little Cypress Bayou 242 471 415 287 155 96 26 10 10 19 65 144
Appreciably more fish were collected from Big 

Cypress 02 (596) in summer 2010 compared to Black 

Cypress (273) or Little Cypress (359), but the total number 

of fish species collected among the three reaches was 

similar (fig. 2). Longear sunfish was the most abundant 

fish species collected from all three streams. In all three 

streams, there were far more fish species in the runs than 

in the pools. The total number of fish species was largest in 

slow run mesohabitats at Big Cypress 02, fast runs at Black 

Cypress, and slow runs at Little Cypress. 

Fish counts were standardized by determining the 

catch-per-unit-effort as the number of fish collected in 

30 seconds of electrofishing. The catch per unit effort of 

native minnows was largest in fast runs at Big Cypress 02. 

Big Cypress Bayou at 

confluence of French 

Creek, Jefferson, Texas

(Big Cypress 02)

Black Cypress Bayou 

near U.S. Highway 59 

near Jefferson, Texas

(Black Cypress)

Little Cypress Bayou 

near U.S. Highway 59 

near Jefferson, Texas

(Little Cypress)

0

5

10

15

20

25

30

Total number of fish species

*

* Mesohabitat type not present.

Mesohabitat type

 Slow runs

 Fast runs

 Channel pools

 Margin pools

EXPLANATION

Figure 2. Number of fish species collected 

by mesohabitat type from sites on Big Cypress 

Bayou, Black Cypress Bayou, and Little Cypress 

Bayou in the Big Cypress Basin in northeastern 

Texas, 2010–11.

Typical size largemouth bass collected at the upstream reach of Big 

Cypress Bayou (Big Cypress 02), Texas, July 2010. 

U.S. Geological Survey scientists measuring physical 

characteristics of Big Cypress Creek, Texas, July 26, 2011. 

Photograph taken by James B. Moring, U.S. Geological Survey
U.S. Geological Survey scientists collecting fish from Big Cypress 

Creek, Texas, July 27, 2011. Photograph taken by Erin C. Sewell, U.S. 

Geological Survey.

Mussel collected from the Big Cypress Basin in Texas.

More species of native minnows, including the 

ironcolor and emerald shiner, were collected 

from Little Cypress relative to all other 

mesohabitats at all sites. 

About 14 percent more fish were collected 

from Big Cypress 02 in 2010 relative to 2011, 

and about 18 percent fewer fish species were 

identified in 2011 at this site compared to 2010. 

Longear sunfish, which was the most abundant 

fish species collected in 2010, was second to 

western mosquitofish in 2011. 

A total of 15 species and 182 individuals of 

freshwater mussels were collected. Big Cypress 

01 was the most species rich site with 13 species, 

and washboards were the most abundant species 

overall. Mussels were not collected from Little 

Cypress because there was no flow in this stream 

during the targeted sampling period in 2011. 

In the absence of flow during fall 2011, 

the reach at Black Cypress was reduced to 

four isolated pools, and the reach at Little 

Cypress was reduced to three isolated pools. 

Dissolved oxygen, temperature, pH, and specific 

conductance data were collected from the pools 

because it was hypothesized that these conditions 

would be the most limiting with respect to 

aquatic life. Dissolved oxygen concentrations 

ranged from 0.58 milligrams per liter (mg/L) to 

4.79 mg/L at Black Cypress and from 0.24 mg/L 

to 5.33 mg/L at Little Cypress; both sites 

exhibited a stratified pattern in dissolved oxygen 

concentrations along transect lines, but the pattern 

was less pronounced at Black Cypress.

This fact sheet is based on the following USGS report:

Braun, C.L., and Moring, J.B., 2013, Baseline assessment 

of physical characteristics, aquatic biota, and selected 

water-quality properties at the reach and mesohabitat 

scale for reaches of Big Cypress, Black Cypress, and 

Little Cypress Bayous, Big Cypress Basin, northeastern 

Texas, 2010–11: U.S. Geological Survey Scientific 

Investigations Report 2013–5058, 90 p.

References Cited

Caddo Lake Institute, 2010, Environmental flow regime 

and analysis recommendations report: accessed on 

June 30, 2012, at http://www.caddolakeinstitute.us/

docs/flows/8.10_Recommendations_Report/Cypress_

SB3_20100826_Main.pdf.

Konrad, C.P., 2010, Monitoring and evaluation of 

environmental flow prescriptions for five demonstration 

sites of the Sustainable Rivers Project: U.S. Geological 

Survey Open-File Report 2010–1065, 22 p.

Pardo, Isabel, and Armitage, P.D., 1997, Species 

assemblages as descriptors of mesohabitats: 

Hydrobiologia, v. 344, p. 111–128, accessed 

May 6, 2013, at http://link.springer.com/content/

pdf/10.1023%2FA%3A1002958412237.pdf.

Christopher L. Braun and James B. Moring

For additional information, contact 

Director, Texas Water Science Center

U.S. Geological Survey

1505 Ferguson Lane

Austin, Texas 78754–4501

http://tx.usgs.gov/

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