Environmental Flowsecological principles, applications,
and lessons from New Mexico
Maceo C. MartinetMarilyn Myers
W. Jason Remshardt
U.S. Fish and Wildlife ServiceAlbuquerque, NM
American Fisheries Society Western Division Conference 2009
Environmental Flows: definition
Describe the quantity, timing, and qualityof water flows required to sustain
freshwater ecosystems
and the human livelihoods and well-being of those that depend on these ecosystems*
*The Brisbane Declaration, 2007: > 750 scientists from >50 countries
Environmental Flows: Principle I
• The natural flow regime is a major force shaping the physical habitat biotic
composition
Bunn and Arthington 2002, Naiman et al. 2002, Arthington et al. 2006, Richter et al., 2003, Poff et al., 1997
Time
Dis
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arg
e
• Redistributing sediment, debris, nutrients
• Channel geomorphology
• Habitat patches disturbance
complexity of runs, riffles, pools, back channels….
Base flows can affect availability of habitat and connectivity between patches
Environmental Flows: Principle II• Aquatic and riparian species have adapted
to natural flow regimes (eg. variability and seasonality)
Time
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CPUE vs DischargeSeasonal pattern life history patternsCottonwood seed dispersal
coincides with receding floodwater
Jul & AugBunn and Arthington 2002, Naiman et al. 2002, Poff et al., 1997
Environmental Flows: Principle III
• Maintain longitudinal and lateral hydrologic connectivity
Vannote et al, 1980, Bunn and Arthington 2002, Naiman et al. 2002Time
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• Overbank flooding
• Upstream ↔ downstream
Environmental Flows: Applications
• 1996 - South Africa’s New Constitution– protection of env. flows are fundamental to healthy
environment healthy society
• 2007 - Maine water use standards– Protection based on natural variations in flow
• 2007 – Montana legislature– Protecting env. flows from groundwater withdrawals
– 2 water bodies are connected
Tharme 2003, Smith 2008
Gila River (Gila, NM) Natural Flow Regime (72-yr record)
• Plans to divert ~ 14,000 acre-ft per year for SW New Mexico• NM Governor and water officials embraced collaborative, science-
based approach • Preliminary environmental flow analysis low flow and small
floods likely altered, spring and winter monthsHaney 2006
Pecos
• Water management ≠ natural flow regime
• Block release flows irrigators
• Different hydrograph if we take ecosystem into account
Pecos bluntnose shiner, interior least tern
San Juan
Pre-dam High spring flows, low base flows (lots of variability)
-
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
30-S ep 19-Nov 8-J an 27-F eb 17-Apr 6-J un 26-J ul 14-S ep 3-Nov
Dis
ch
arg
e -
cfs
P re-Navajo Dam 1929-61
-
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
30-S ep 19-Nov 8-J an 27-F eb 17-Apr 6-J un 26-J ul 14-S ep 3-Nov
Dis
ch
arg
e -
cfs
P re Navajo Dam 1929-61 P os t dam 1962-1991
-
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
30-S ep 19-Nov 8-J an 27-F eb 17-Apr 6-J un 26-J ul 14-S ep 3-Nov
Dis
ch
arg
e -
cfs
P re-dam 1929-61 P os t dam 1962-1991 R es earc h P eriod 1993-2008
Post-dam native fish decline
Colorado pikeminnow (listed in 1967) razorback sucker (listed in 1991)
Research Period natural flow regime key to species recovery
- Higher peak flows = build and clean fish habitat (eg. cobble bars, backwaters)- Lower base flows = optimize availability of habitat (eg. backwaters)- Flow recommendations using statistical variability of natural
hydrograph (eg. flows > 5,000 cfs at least 21 days, >10,000 cfs 5 days or more)
Rio Grande
- Quantity and variability of annual peak flows ↓- Sediment starved and stable river bank incised
channel, little overbank flooding
Integrating Environmental Flows
• Progress in how to maintain healthy water ways application
• climate change living within ecological limits
• Challenge help public understand and define sustainability thresholds
Postel and Richter, 2003