Transcript FWI Studies - Caddo Lake Institute

Ecosystem Flows
Hydrology and Connectivity
Joe Trungale
October 2, 2006
Organization
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Sustainable Rivers Program to Caddo Watershed
and Building Blocks Recommendations
Hydrology and Connectivity
Review of building block recommendations and
research priorities.
 Status report of on-going work.
 Strategy for refinements to flow recommendations
and research priorities.
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Little and Black Cypress
Process to Develop
Ecosystem Flow Recommendations
December 2004
On-going
April 2005
May 2005
Ecosystem Flow Components
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Flow prescription considers the
flow regime (Large Floods, Small Floods, High Flow
Pulses, Low Flows, and Extreme Low Flows)
 inter-annual variation (wet, normal and dry years)
 riverine and lake components (hydrology, biology,
geomorphology, water quality and connectivity)
 measures (magnitude, frequency, duration, timing
and rate of change)
 ecosystem response
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Instream Flow Building Blocks
Big Cypress Creek/ Caddo Lake
6,000-10,000 cfs for 2-3 days
Every 3-5 years
*Maintain aquatic habitat in floodplain
* Riparian seed dispersal
* Inhibition of upland vegetation for both creek & lake
*Seed dispersal
* Vegetation removal
20,000 cfs for 2-3 days
Every 10 years
*For channel migration
Floods
6,000 cfs for 2-3 days
Every 2 years
* For channel maintenance
High Flow
Pulses
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)
Low Flows
Key
Wet Year
Avg Year
Dry Year
40 – 536 cfs
Maintain biodiversity and connectivity (backwater & oxbows)
268-347 cfs
Pre-dam median
390 - 79 cfs
Benthic drift & dispersal, fish spawning
35 - 40 cfs
Fish habitat
40 - 117 cfs
Pre-dam median
90 cfs
Fish habitat
218 – 49 cfs
Spawning habitat
13 - 6 cfs
Maintain aquatic diversity
40 - 90 cfs
Fish habitat
JAN
FEB
MAR
APR MAY
JUN
JUL
AUG
SEP
OCT NOV
DEC
Lake Level Building Blocks
Caddo Lake
Inhibition of upland
vegetation
Elevated
Lake
Level
Refill for
Nutrient and
sediment flush
Duration:
about 15 days
Normal
Lake Level
Low Lake
Level
Summer draw down to prepare
for nutrient flush.
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”
Duration: every year for 1 ten
year period
JAN
FEB
MAR
APR MAY
JUN
JUL
AUG
SEP
OCT NOV
DEC
Hydrology
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Stream gages
Lake elevation
Seasonal patterns of natural river flow and lake
level fluctuation
Response of the natural system to human
influences
Water development plans
Groundwater
Elevation (ft)
Caddo Lake Elevation
184
182
180
178
176
174
172
170
168
166
164
1933
Elevation
Spillway
Wetlands
LOP
1943
1953
1963
1973
Date
1983
1993
2003
184
182
180
178
176
174
172
170
168
166
164
Date
2/2/88
1/23/88
1/13/88
1/3/88
12/24/87
12/14/87
14,000
12,000
10,000
8,000
6,000
4,000
2,000
0
12/4/87
Elevation (ft)
Caddo Lake Elevation
High Lake Elevation in Jan 1988
184
182
180
178
176
174
172
170
168
166
164
14,000
12,000
10,000
8,000
6,000
4,000
2,000
Date
3/30/01
3/20/01
3/10/01
2/28/01
2/18/01
0
2/8/01
Elevation (ft)
Caddo Lake Elevation
High Lake Elevation in Feb-March 2001
Seasonal Flow Patterns
EFC Monthly Low Flow s
Little Cypress
Black Cypress
1947-2005 (59 years)
1969-2005 (37 years)
25%
25%
50%
75%
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 system to
human influences
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To what extent have the base, high pulse, and overbank
flows in the river changed over time in response to
human influences? Have extreme low flows (i.e.,
subsistence flows) become more frequent or extreme?
What are the primary human influences on the flow
regime, and where do these impacts occur?
What types of water development activities are planned
for the future, and how might those developments
influence river flows?
Water Development
Dry
Natural Current
Jan 87%
62%
Feb 98%
72%
Mar 92%
69%
Apr 84%
66%
May 85%
68%
Jun 85%
65%
Jul 87%
62%
Aug 86%
57%
Sep 76%
50%
Oct 54%
29%
Nov 63%
37%
Dec 79%
49%
SB1
53%
67%
60%
63%
66%
58%
51%
46%
44%
20%
28%
46%
Full
35%
47%
42%
49%
46%
42%
35%
43%
37%
10%
16%
27%
Percent Excedence
Average
Natural Current
SB1
66%
43%
39%
78%
59%
48%
80%
62%
54%
76%
60%
58%
80%
66%
64%
78%
55%
50%
80%
44%
39%
70%
38%
34%
55%
32%
25%
54%
29%
20%
63%
37%
28%
75%
46%
45%
Full
28%
37%
38%
41%
42%
35%
23%
12%
14%
10%
16%
26%
Wet
Natural Current
SB1
53%
38%
36%
68%
54%
43%
72%
58%
50%
69%
57%
53%
69%
58%
53%
67%
49%
46%
69%
32%
31%
70%
38%
34%
55%
32%
25%
51%
27%
20%
62%
37%
28%
57%
35%
34%
Full
25%
31%
34%
36%
37%
31%
19%
12%
14%
10%
16%
18%
Connectivity/Hydraulics
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Hydraulic modeling and
flood hazard mapping
Relationships between river
and lake stages
Relationships between river
flow and hydraulic habitat.
(i.e. distribution of velocities
and depths in the river
channel)
Longitudinal connectivity
Lateral connectivity
Precipitation
Floodplain
Headwaters
Wetlands
Tributary
Watershed
Boundary
Hillside
Bankside
Water Table
Groundwater
Hydraulic Modeling /
Wetland Inundation Mapping
BC y pres s1
Plan: Plan 02
3/20/ 2006
.13
.04
.13
200
Legend
WS PF 9
BC y pres s1
220
Plan: Plan 02
WS PF 8
3/20/ 2006
WS PF 7
Legend
WS PF 6
WS PF 9
WS PF 5
WS PF 8
WS PF 4
WS PF 7
WS PF 3
190
WS PF 6
WS PF 2
WS PF 5
WS PF 1
WS PF 4
Ground
WS PF 3
Bank Sta
WS PF 2
WS PF 1
200
Ground
180
170
Elevation (ft)
Elevation (ft)
180
160
160
150
140
140
0
2000
4000
6000
8000
10000
12000
14000
Station (ft)
120
20
30
40
50
Main Channel Distance (mi )
60
70
80
Watershed Protection Plan
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Control of Caddo Lake levels
Ecosystem flows
Groundwater-Surface Water interaction
Flood protection and mapping
Drought
Capacity of Big Cypress Creek to handle
releases from Lake O’ the Pines
Topics for Breakout Sessions
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Subsistence Flows
Little and Black Cypress Building Blocks and
Research Priorities
Wetland Flood Plan Inundation
Groundwater – Surface Water Interactions