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Restoring the Pecos River atBitter Lake National Wildlife Refuge
Paul Tashjian, USFWS, Water ResourcesPaul_Tashjian@fws.gov 505-248-7958
Aquatic Species of Bitter Lake NWR24 fish species, 19 are native
3 Federally Threatened or Endangered52 Amphibians and Aquatic Reptile species50+ dragonfly species
Most diverse in North America2 Native Amphipods species (snails)
State and Federal endangered species352 Bird Species use the RefugeMigratory Birds
Sandhill Cranes, Snow Geese, Canadian GeeseSnowy Plover nesting area (only site in New Mexico)
Wetland Plant Species: saltgrass marsh community, Endangered Pecos Puzzle Sunflower
Most biologically significant wetland in New MexicoThe Roswell Area Spring System and Pecos River are
Unsung National Natural Treasures
Pecos River at Fort SumnerWater Year 1928 Hydrograph
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10/1 10/31 11/30 12/30 1/29 2/28 3/30 4/29 5/29 6/28 7/28 8/27 9/26
flow
(cfs
)
12,000 cfs peak 2200 cfs peak
spring run-off
summer storms
Pecos River at Fort SumnerWater Year 1984 Hydrograph
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10/1 10/31 11/30 12/30 1/29 2/28 3/30 4/29 5/29 6/28 7/28 8/27 9/26
flow
(cfs
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Pecos River at Acme1984 Hydrograph
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10/1 10/31 11/30 12/30 1/29 2/28 3/30 4/29 5/29 6/28 7/28 8/27 9/26
flow
(cfs
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Tailwater
Farmland
Rangeland
-4
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-1
0
dist
ance
bel
ow d
atum
(m
eter
s)
1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77
Huey Park
Rio Felix
380 Bridge
Gasline Crossing
Atkin's Ranch
Cedar Creek
Old Fort
60 Bridge
distance from datum (meters)
Station Name
Bitter Lake NWR
Tail water
Rangeland
Farmland
Pecos River Between Sumner and Brantley Reservoirs: Channel Morphology Overview
Middle Pecos River Sediment Overview
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0.01 0.1 1 10 100
particle size (mm)
TailwaterRangeland
Farmland
SandSi l t-Clay Gravel
Atkins Ranch Habitat Site: 1995 and 1996 Cross Sections
-3.5
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-2.5
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-1
-0.5
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meters
met
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36cfs: Well sorted sand. Many large point and in-channel bars (70m wide with 200m crest spacing). Small sand dunes and ripples in activechannel.
Rio Felix Habitat Site: 1992-1996 Cross Sections
-3.5
-3
-2.5
-2
-1.5
-1
-0.5
01 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59
meters
met
ers
37cfs: Fine sand and some silt. Some small point bars (5m wide with 25m-200m spacing). Sand ripples mobile in active channel.
-4
-3
-2
-1
0
dist
ance
bel
ow d
atum
(m
eter
s)
1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77
Huey Park
Rio Felix
380 Bridge
Gasline Crossing
Atkin's Ranch
Cedar Creek
Old Fort
60 Bridge
distance from datum (meters)
Station Name
Bitter Lake NWR
Tail water
Rangeland
Farmland
Pecos River Between Sumner and Brantley Reservoirs: Channel Morphology Overview
Pecos River Geomorphic Setting of the Refuge
• Junction between quality habitat to the north and poor habitat to the south– quality habitat marked by higher width to depth
ratios and active sand bed– poorer habitat marked by low width to depth
ratios, tamarisk lined, inactive sand/silt bed• River incised on Refuge 1942-1953• Modern River is very active on Refuge
Why do Pecos River Restoration at Bitter Lake NWR?• At transition between quality and poor habitat on Middle
Pecos River.• Channel is very active. Restoration will nudge it towards a
healthier system. • The Pecos at the Refuge is always wet: Perennial flows on
the Pecos begin at Bitter Lake NWR• Ideal location for pelagic fishes habitat: acts as a catchment
for upstream fish eggs • Establish greater continuity in habitat with upper quality
reach.• Ties Refuge into Pecos River conservation.• Refuge can act as a showcase for the Pecos.• Potential societal benefits: ecotourism, water salvage,
flood control, fire control.
Restoration Alternatives -General Strategies
• Vegetation removal• Bank lowering• Reworking channel morphology• Native vegetation plantings• Diverting river into original meanders
Salt Cedar removalReactivate channel mobilityBank lowering: connecting the floodplain better in areas where river is activeNative vegetation plantning
Reconnect Oxbow 4Improves spring connection to Pecos River
Salt Cedar RemovalNative vegetation plantingAllow River to establish habitat under with hydrology
Water Budget
• Groundwater gradient is towards river– Gaining rivers are locations of accruement for riparian ET reductions
• Increased water:– Reconnection of springs in Oxbow 4– Reduction of ET from tamarisk removal
• Decreased water:– Increase in area of base flow from connecting Oxbow 4– Increase in overbank flows from removing bankline levees
• Net estimate: 2000af/ammum increase in water budget
Water Budget (continued)
• Net estimate: 2000af/ammum net increase in water budget• Estimate takes a very conservative approach
– The future condition of the removed salt cedar acres will be a mix of salt cedar, willow and grassland. This percent is estimated to be 20% salt cedar, 30% willow, 20% Saltgrass and 30% other grassland.
– Increase in overbank flows assumes flows greater than 200cfs will result in a complete flooding of 43 additional acres. In reality flows greater than 1200cfs will inundate these areas and flows greater than 5000cfs will result in complete flooding.
– Assumes a current condition for spring contribution to Oxbow 4 of 6 acres. This is about half of what the lowest acreage is as obtained from aerial photography for the period 1996-2004.
10/97: 15 acres of open water
Re-vegetation Issues
• What was the native riparian vegetation community of the Pecos River at Bitter Lake NWR?
• Coyote Willow reveg techniques– Conceptual reveg design being conducted by Parametrix
(Todd Caplan)• Grassland component
– Sporabilis arodis (alkali sacaton)– Distichilis spicata (salt grass)
• What examples are there of native revegetationsuccesses along Middle Pecos River?
QUESTIONS?
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