TWCA Annual Convention 2018

1. BrazosRiverAuthority
Freshwater mussels, why do
we care?
Presented by
Tiffany Morgan
Environmental and Compliance Manager

2. BrazosRiverAuthority
Candidate-Listed Freshwater
Mussels in Brazos River Basin
Texas Fawnsfoot (Truncilla macrodon)
False spike (Fusconaia mitchelli)*
*Courtesy of Dr. Charles Randklev
Smooth Pimpleback (Quadrula
houstonensis)

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4. BrazosRiverAuthority
Status Recommendation
Schedule
• Texas Fawnsfoot – 2018
• False Spike – 2018
• Smooth Pimpleback - 2020
Smooth pimpleback in Navasota River.

5. BrazosRiverAuthority
Endangered Species Act
• Since 1973, the ESA has proven to be one of the
nation’s strongest conservation laws
– Has been widely upheld in the court system
– Never substantially defeated
• ESA can and has affected state-based water rights
and regulations in other states
– Can limit the traditional exercise of established water
rights
– Restrict or modify new water projects
– Any water use that results in the direct or incidental
take or harm of listed species falls within the ESA’s
reach
• ESA’s ability to preempt state law derives from US
Constitution’s Supremacy Clause

6. BrazosRiverAuthority
Water Projects Impacted by ESA
• Cappaert v. United States – 1976 – Nevada – desert
pupfish
– Stopped ground water pumping by private landowners
• TVA v. Hill – 1978 - Tennessee - snail darter
– Halted construction on dam
• Riverside Irrigation District v. Andrews – 1983 –
Nebraska – whooping crane
– Dam never built
• Carson-Truckee Water Conservancy District v.
Clark – 1984 – California – cui-ui and cutthroat trout
– ESA needs trump municipal and industrial water use
– Changed water releases and pumping from a reservoir

7. BrazosRiverAuthority
ESA Quagmires
• Tri-State Water Wars – (1990 – present) - Alabama,
Florida, and Georgia – multiple endangered
mussels
– Too many suits to summarize briefly
• California State Water Project and Central Valley
Project (2007-present) – California – delta smelt,
Chinook and steelhead salmon, southern resident
orca
– Too many suits to summarize briefly
– Requires changes in pumping from rivers and deltas
impacting municipalities, agriculture and industry
– In 2011 and 2015, Supreme Court refused to limit the
reach of ESA

8. BrazosRiverAuthority
Statements of Concern from
Texas Hornshell Proposal to
List
• State Water Plan proposed reservoir and
groundwater projects cited as an immediate
threat
• Water management/release strategies will be
required
• Improved wastewater discharge quality
• Sediment control strategies will be needed

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Threats

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• Reservoirs
– Controlled systems
rarely mimic natural
flow regimes
– Scouring of riverbed
• Groundwater
pumping
• Drought
• Climate change -
further decline
Modified/Reduced Stream Flow

11. BrazosRiverAuthority
• Dissolved oxygen
>3.0 mg/L*
• Ammonia < 0.7 mg/L*
• Salinity <0.9 ppt*
• Water temperature
• WWTP discharges
• Contaminant spills
• Climate change –
further decline
Water Quality
* Endangered and Threatened Wildlife and Plants; Endangered Species Status for Texas Hornshell, 83 Fed. Reg. 5720 (February 9, 2018) (to be codified at 50 CFR 17).

12. BrazosRiverAuthority
• Smothers mussel
beds
• Low flows
encourage build up
• Less cleansing
flows
• Riparian zone
disruption
• Sand and gravel
mining
Sedimentation

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• Population
fragmentation and
isolation
• Reservoirs
• Low-water dams
• Low-water
crossings
• Pipelines
Barriers to Fish Host Movement

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• Will exacerbate the
previous four
threats
Climate Change

15. BrazosRiverAuthority
Brazos
River
Authority