Ecosystem FlowsEcosystem FlowsHydrology and Hydrology and ConnectivityConnectivity

Joe TrungaleJoe Trungale

October 2, 2006October 2, 2006

OrganizationOrganization

Sustainable Rivers Program to Caddo Sustainable Rivers Program to Caddo Watershed and Building Blocks Watershed and Building Blocks RecommendationsRecommendations

Hydrology and ConnectivityHydrology and Connectivity Review of building block Review of building block

recommendations and research priorities. recommendations and research priorities. Status report of on-going work.Status report of on-going work. Strategy for refinements to flow Strategy for refinements to flow

recommendations and research priorities.recommendations and research priorities. Little and Black CypressLittle and Black Cypress

Process to Develop Process to Develop Ecosystem Flow Ecosystem Flow

RecommendationsRecommendationsDecember 2004

April 2005

May 2005

On-going

Ecosystem Flow Ecosystem Flow ComponentsComponents

Flow prescription considers the Flow prescription considers the flow regime (Large Floods, Small Floods, High flow regime (Large Floods, Small Floods, High

Flow Pulses, Low Flows, and Extreme Low Flows) Flow Pulses, Low Flows, and Extreme Low Flows) inter-annual variation (wet, normal and dry years) inter-annual variation (wet, normal and dry years) riverine and lake components (hydrology, biology, riverine and lake components (hydrology, biology,

geomorphology, water quality and connectivity)geomorphology, water quality and connectivity) measures (magnitude, frequency, duration, measures (magnitude, frequency, duration,

timing and rate of change)timing and rate of change) ecosystem responseecosystem response

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Instream Flow Building BlocksBig Cypress Creek/ Caddo Lake

Low Flows

High FlowPulses

Floods

6,000-10,000 cfs for 2-3 daysEvery 3-5 years

*Maintain aquatic habitat in floodplain* Riparian seed dispersal

* Inhibition of upland vegetation for both creek & lake*Seed dispersal

* Vegetation removal20,000 cfs for 2-3 days

Every 10 years*For channel migration

6,000 cfs for 2-3 days Every 2 years

* For channel maintenance

Key

Dry Year

Avg Year

Wet Year90 cfs

Fish habitat218 – 49 cfs

Spawning habitat13 - 6 cfs

Maintain aquatic diversity40 - 90 cfsFish habitat

268-347 cfsPre-dam median

390 - 79 cfsBenthic drift & dispersal, fish spawning

35 - 40 cfsFish habitat

40 - 117 cfsPre-dam median

40 – 536 cfsMaintain biodiversity and connectivity (backwater & oxbows)

1,500 cfs for 2-3 days 3-5X a year every year

* 1 occurring in March for Paddlefish* Sediment transport, oxbow connectivity

•Waterfowl habitat flushing(Includes December)

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Lake Level Building Blocks

Caddo Lake

Low Lake Level

Normal Lake Level

Elevated Lake Level

Inhibition of upland vegetation

Summer draw down to prepare for nutrient flush.

Duration: every year for 1 ten year period

Refill for Nutrient and sediment flush

Duration: about 15 days

This chart is based on the assumption that the lake would benefit from nutrient flushing. Unknown’s include (but are not limited to) the quality of the refill water, impacts and on aquatic species and how long it will take to drop down. This idea is currently “parked”

HydrologyHydrology

Stream gagesStream gages Lake elevationLake elevation Seasonal patterns of natural river Seasonal patterns of natural river

flow and lake level fluctuationflow and lake level fluctuation Response of the natural system to Response of the natural system to

human influenceshuman influences Water development plansWater development plans GroundwaterGroundwater

Caddo Lake Elevation

164

166

168

170

172

174

176

178

180

182

184

1933 1943 1953 1963 1973 1983 1993 2003

Date

Ele

vatio

n (f

t)

ElevationSpillwayWetlandsLOP

Caddo Lake ElevationHigh Lake Elevation in Jan 1988

164166168170172174176178180182184

12/4

/87

12/1

4/87

12/2

4/87

1/3/

88

1/13

/88

1/23

/88

2/2/

88

Date

Ele

vatio

n (f

t)

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

Caddo Lake ElevationHigh Lake Elevation in Feb-March 2001

164166168170172174176178180182184

2/8/

01

2/18

/01

2/28

/01

3/10

/01

3/20

/01

3/30

/01

Date

Ele

vatio

n (f

t)

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

Seasonal Flow Patterns Seasonal Flow Patterns EFC Monthly Low Flows

Little Cypress Black Cypress

1947-2005 (59 years) 1969-2005 (37 years)

25% 50% 75% 25% 50% 75%

January 112 242 462 125 222 322

February 186 417 570 201 300 366

March 219 415 548 242 306 382

April 158 287 466 140 205 327

May 86 155 320 80 156 210

June 38 96 179 42 95 191

July 12 26 80 11 32 63

August 1 10 30 1 5 14

September 1 10 33 1 4 19

October 5 19 53 4 13 45

November 18 65 133 19 74 158

December 68 144 250 91 209 294

Response of the natural Response of the natural system to human influencessystem to human influences

To what extent have the base, high pulse, and To what extent have the base, high pulse, and overbank flows in the river changed over time overbank flows in the river changed over time in response to human influences? Have in response to human influences? Have extreme low flows (i.e., subsistence flows) extreme low flows (i.e., subsistence flows) become more frequent or extreme? become more frequent or extreme?

What are the primary human influences on the What are the primary human influences on the flow regime, and where do these impacts flow regime, and where do these impacts occur? occur?

What types of water development activities are What types of water development activities are planned for the future, and how might those planned for the future, and how might those developments influence river flows?developments influence river flows?

Water DevelopmentWater Development

Percent ExcedenceDry Average Wet

Natural Current SB1 Full Natural Current SB1 Full Natural Current SB1 FullJan 87% 62% 53% 35% 66% 43% 39% 28% 53% 38% 36% 25%Feb 98% 72% 67% 47% 78% 59% 48% 37% 68% 54% 43% 31%Mar 92% 69% 60% 42% 80% 62% 54% 38% 72% 58% 50% 34%Apr 84% 66% 63% 49% 76% 60% 58% 41% 69% 57% 53% 36%May 85% 68% 66% 46% 80% 66% 64% 42% 69% 58% 53% 37%Jun 85% 65% 58% 42% 78% 55% 50% 35% 67% 49% 46% 31%Jul 87% 62% 51% 35% 80% 44% 39% 23% 69% 32% 31% 19%

Aug 86% 57% 46% 43% 70% 38% 34% 12% 70% 38% 34% 12%Sep 76% 50% 44% 37% 55% 32% 25% 14% 55% 32% 25% 14%Oct 54% 29% 20% 10% 54% 29% 20% 10% 51% 27% 20% 10%Nov 63% 37% 28% 16% 63% 37% 28% 16% 62% 37% 28% 16%Dec 79% 49% 46% 27% 75% 46% 45% 26% 57% 35% 34% 18%

Connectivity/HydraulicsConnectivity/Hydraulics Hydraulic modeling and Hydraulic modeling and

flood hazard mappingflood hazard mapping Relationships between Relationships between

river and lake stagesriver and lake stages Relationships between Relationships between

river flow and hydraulic river flow and hydraulic habitat. (i.e. distribution habitat. (i.e. distribution of velocities and depths of velocities and depths in the river channel)in the river channel)

Longitudinal Longitudinal connectivity connectivity

Lateral connectivityLateral connectivity

Floodplain

Precipitation

WatershedBoundary

HeadwatersWetlands

Tributary Hillside

Bankside

Groundwater

Water Table

0 2000 4000 6000 8000 10000 12000 14000140

150

160

170

180

190

200

BCypress1 Plan: Plan 02 3/20/2006

Station (ft)

Ele

vatio

n (ft

)

Legend

WS PF 9

WS PF 8

WS PF 7

WS PF 6

WS PF 5

WS PF 4

WS PF 3

WS PF 2

WS PF 1

Ground

Bank Sta

.13 .04 .13

Hydraulic Modeling / Hydraulic Modeling / Wetland Inundation Wetland Inundation

MappingMapping

20 30 40 50 60 70 80120

140

160

180

200

220BCypress1 Plan: Plan 02 3/20/2006

Main Channel Distance (mi)

Ele

vatio

n (ft

)

Legend

WS PF 9

WS PF 8

WS PF 7

WS PF 6

WS PF 5

WS PF 4

WS PF 3

WS PF 2

WS PF 1

Ground

Watershed Protection Watershed Protection PlanPlan

Control of Caddo Lake levels Control of Caddo Lake levels Ecosystem flowsEcosystem flows Groundwater-Surface Water Groundwater-Surface Water

interaction interaction Flood protection and mappingFlood protection and mapping DroughtDrought Capacity of Big Cypress Creek to Capacity of Big Cypress Creek to

handle releases from Lake O’ the Pines handle releases from Lake O’ the Pines

Topics for Breakout Topics for Breakout SessionsSessions

Subsistence FlowsSubsistence Flows Little and Black Cypress Building Little and Black Cypress Building

Blocks and Research PrioritiesBlocks and Research Priorities Wetland Flood Plan InundationWetland Flood Plan Inundation Groundwater – Surface Water Groundwater – Surface Water

InteractionsInteractions