Water Quality in the Caddo Lake Watershed

Caddo Lake Water Quality

Cypress Creek Clean Rivers Program

Monitoring Station Types

• Routine monitoring is used to follow trends and to identify water quality changes in the major watersheds.

• Systematic monitoring is a screening tool used to detect potential concerns. Typically placed on the smaller streams. Biological monitoring is a key factor.

• Special study monitoring projects are located and designed to address a specific concern.

Water Quality Parameter Sets

• Field– Temperature– Dissolved Oxygen– Conductivity– pH– Secchi Depth

Diel Sampling

• Conventional– Suspended Solids– Dissolved Solids

• Chloride• Sulfate• Hardness• Alkalinity

– Nutrients –Ammonia, Nitrate & Organic Nitrogen, Phosphorus

– Chlorophyll– Bacteria

Other Sample Sets

• Metals in Water and in Sediment– aluminum, arsenic, chromium, copper, nickel,

silver, zinc, barium, molybdenum, selenium, iron, and manganese

• Habitat & Biological– Fish & Macroinvertebrates (Benthics)

Average Annual Inflow to Caddo Lake

During 1979 – 2004

Average Annual Inflow to Caddo Lake

During 1979 – 2004

Total Phosphorus Measurements in Segment 0402 Cypress Creek Basin 1973-2006

0

5

10

15

20

25

30

35

40

45

Y ear

16936

16935

16934

16705

16254

16253

15511

15135

15022

14997

14474

14471

13630

10295

10294

10248

10247

10246

10245

10244

Black Cypress BayouStation 10245

pH Dissolved Oxygen (mg/l)

• Average 6.4 Average 7.0• Median 6.4 Median 6.6• Range 5.3-8.6 (71) Range 2.3-11.8 (72)

Chlorophyll a g/l)

Average 7.65 Median 5.00

Range 0.20-58.00 (65)

Black Cypress Bayou Station 10245 DO Saturation Deficits

R2 = 0.0229

-1.0

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

1/1/74

6/24/79

12/14/84

6/6/90

11/27/95

5/19/01

mg

/l

DO 24HR Min

DO 24HR Max DO Range

DO 24HR Average

Station 10245

07/18/2000 3.3 3.7 0.4 3.5

08/24/2000 0.4 2.2 1.8 1.1

11/21/2000 10.2 10.5 0.3 10.3

04/06/2001 7.1 6.2 -0.9 6.7

05/04/2001 6.3 5.9 -0.4 6

06/08/2001 5.4 5.5 0.1 5

07/03/2001 5.6 5.8 0.2 5.7

08/08/2001 2.1 3.4 1.3 3.1

09/11/2001 5.7 5.8 0.1 5.7

10/19/2001 7.7 7.9 0.2 7.8

04/13/2005 6.5 6.7 0.2 6.6

05/06/2005 7.4 7.8 0.4 7.6

Average 0.3 5.8

Nitrogen (mg/l) Station 10245

Nitrate + Nitrite Nitrate

Average 0.11 0.13

Median 0.10 0.08

Range 0.04-0.28 (26) 0.02-0.79 (38)

Ammonia TKN

Average 0.08 0.58

Median 0.05 0.54

Range 0.0-0.277 (65) 0.03-1.27 (34)

Total Phosphorus (mg/l)

Station 10245 10246

Average 0.08 0.10

Median 0.08 0.08

Range 0.01-0.26 (66) 0.03-0.20 (25)

Black Cypress Bayou, Station 10245 Total Phosphorus Concentrations

R2 = 2E-08

0

0.05

0.1

0.15

0.2

0.25

0.3

1/1/74 5/24/81 10/14/88 3/6/96 7/28/03

mg/

l

Black Cypress Bayou: Average Seasonal Flows

40%

10%9%

41% Spring

Summer

Fall

Winter

Black Cypress Bayou: Seasonal Phosphorus Concentrations (mg/l)

0.09

0.11

0.08

0.06

Spring

Summer

Fall

Winter

Black Cypress Bayou: Seasonal Phosphorus Loads (kg)

11619

37622301

8045Spring

Summer

Fall

Winter

Black Cypress Bayou: Average Seasonal Nitrogen Concentrations (mg/l)

0.81

0.660.72

0.59

Spring

Summer

Fall

Winter

Black Cypress Bayou: Seasonal Nitrogen Loads (kg)

105140

2184020867

78518Spring

Summer

Fall

Winter

Little Cypress Bayou Station 10332

pH Dissolved Oxygen (mg/l)

Average 6.6 7.0

Median 6.6 6.9

Range 5.2-8.6 (157) 2.3-13.7 (154)

Chlorophyll a g/l)

Average 6.66 Median 5.00

Range 0.20-58.00 (65)

Station 10332, Little Cypress Bayou, Saturation Deficits

R2 = 0.0022

-4.0

-2.0

0.0

2.0

4.0

6.0

8.0

10.0

DO

mg/

l

DO 24HR MinDO 24HR

Max DO RangeDO 24HR Average

Station 10332

4/2/02 6.8 7.3 0.5 7

5/3/02 4.4 4.7 0.3 4.5

6/4/02 5 5.4 0.4 5.2

7/2/02 4.4 4.8 0.4 4.6

8/1/02 3.9 4.5 0.6 4.2

9/4/02 4.8 5.4 0.6 5

6/3/03 4.3 4.5 0.2 4.4

6/24/03 4.9 5.2 0.3 5

7/25/03 2.8 3.5 0.7 3.1

8/13/03 4.6 5.7 1.1 5

Average 0.5 4.8

Nitrogen (mg/l) Station 10332

Nitrate + Nitrite Nitrate

Average 0.14 0.09

Median 0.10 0.07

Range 0.05-0.40 (68) 0.02-0.26 (22)

Ammonia TKN

Average 0.08 0.76

Median 0.05 0.70

Range 0.01-0.90 (122) 0.20-2.90 (109)

Total Phosphorus (mg/l)

Station 10332 15773

Average 0.11 0.21

Median 0.09 0.14

Range 0.01-1.10 (122) 0.01-1.34 (20)

Little Cypress Bayou: Average Seasonal Flows

42%

10%7%

41% Spring

Summer

Fall

Winter

Little Cypress Bayou: Average Seasonal Total

Phosphorus Concentrations (mg/m3)

0.10

0.15

0.09

0.07

Spring

Summer

Fall

Winter

Little Cypress Bayou: Seasonal Phosphorus Load (kg)

20422

74083337

14773Spring

Summer

Fall

Winter

Little Cypress Bayou: Average Seasonal Total Nitrogen Concentrations (mg/l)

1.07

0.890.70

0.99Spring

Summer

Fall

Winter

Little Cypress Bayou: Seasonal Total Nitrogen Loads

45%

9%5%

41% Spring

Summer

Fall

Winter

Big Cypress Creek Average Seasonal Flows

40%

14%8%

38% Spring

Summer

Fall

Winter

Big Cypress Creek Average Seasonal Flows 1924-1959

47%

12%7%

34% Spring

Summer

Fall

Winter

Big Cypress Creek Average Seasonal Phosphorus Concentrations mg/l)

0.088

0.089

0.054

0.065Spring

Summer

Fall

Winter

Big Cypress Creek Average Seasonal Phosphorus Load (kg)

19872

69642351

13638 Spring

Summer

Fall

Winter

BigBlack

Little0

50000

100000

150000

200000

Average Seasonal Flows (acre-feet)

Spring Summer FallWinter

BigBlack

Little0

5000

10000

15000

20000

25000

Average Seasonal Phosphorus Loads (kg)

Seasonal Turnover (Total Inflow/Caddo Volume, 130,000 acre feet)

3.480

1.0040.674

3.380 Spring

Summer

Fall

Winter

Seasonal Turnover: Big Cypress Flow/Caddo Lake Volume

0.000

0.500

1.000

1.500

2.000

Spring Summer Fall Winter

1925-59

1979-05