Salinity Control on the Pecos River
Robert E. Mace, Ph.D., P.G.
presented at the Multi-State Salinity Coalition’s Salinity SummitJanuary 26, 2012; Las Vegas, NV
figure from Wikimedia Commons
Pecos River
• Length: 929 miles• Drainage Basin: 44,402 square miles• Discharge near Langtry, Texas:– Average of 265 cfs– Maximum of 152,910 cfs– Minimum of 42 cfs
• Empties into Lake Amistad
Pecos River
• Reservoirs– New Mexico -- Texas• Santa Rosa - Red Bluff• Sumner• Avalon• Brantley
• Pecos River Compact (ratified in 1949)• Pecos River Settlement Agreement (2003)
Horsehead Crossing
circa 1850
Permian Evaporite Deposits
from Miyamoto & others (2007)
Sources of Salinity
• Groundwater discharge– Salt springs at Bottomless Lakes
• East of Roswell• 300,000 tons per year
– Salt springs at Malaga Bend• Just north of stateline • 150,000 tons per year• Salinity in river = 4,100 ppm
• Lower flows in river (= less dilution)– Flows at Malaga Bend
• 210,000 acre-feet in 1959• 66,000 acre-feet in 2001
Bottomless Lakes
Malaga Bend
from Miyamoto & others (2007)
Salinity at Red Bluff
Salinity Plot Near Amistad
Impacts
• Red Bluff Reservoir– Salt loading• 478,000 tons per year from Pecos River• 80,000 tons per year from Delaware River
– Outflow• Outflow from reservoir: 410,000 tons/year• TDS of water = 6,000 ppm
– Too high for most crops
• Salinity at Girvin: 12,000 ppm• Salt loading for Lake Amistad
– 26% from Pecos River (10% flow)
Control History
• 1938: NM State Engineer’s Office• notes large amounts of salt discharging into Pecos
River at Malaga• notes source of water from the Rustler Formation
• 1942: USGS (C.V. Theis) estimates the flow and suggests diverting it
• 1954: USGS proposes cutting off the bend or pumping groundwater to intercept the flow
Control History (cont.)
• 1958: Congress authorizes the Malaga Bend Salinity Alleviation Project – First salt control project of its kind in the U.S.– Construction by Bureau of Reclamation– Data collection by USGS– Right of way acquired by NM– Operation and maintenance by Texas
• 1962: Construction starts– 220 ft well– ~2 miles of pipe– Discharge to unlined but compacted 50-acre evaporation pond
Malaga Bend
Control History (cont.)
• 1963: Pumping starts– By December 1964, 1,000 acre-feet of water pumped
removing 300,000 tons of salt– Decreases brine inflow to river by 70 percent– Possible leakage from depression…
• 1963 to 1968– About 3,878 acre-feet of brine is pumped
• 1970: Texas proposes to pump the brine to Culberson County (Texas) for enhanced oil recovery (EOR)
• 1972: Pumping for EOR starts• 1977: EOR pumping stops due to problems with the pump and
casing
Control History (cont.)
• 1993: Pumping stops due to– A need to re-engineer the pond– Concerns that pond was hazard to water fowl– Lack of interest by United Salt Company to operate facility
• 1995: BuRec conducts study of benefits of salt control• 2010: Pecos River Water Quality Coalition Forms
– Currently working with Corps of Engineers • 2012: Pecos River Compact Commissioners work to bring private
company back in to pump well again to produce salt
Members• Texas State Senator Carlos I. Uresti• Texas State Representative Pete Gallego• Texas Pecos River Compact Commissioner• Texas Commission on Environmental Quality• Texas State Soil and Water Conservation Board• Texas Water Development Board• International Boundary & Water Commission Clean Rivers Program• Red Bluff Water Power Control District• International Boundary & Water Commission• Texas Water Resources Institute • Texas A&M AgriLife Research and Extension Center
Initial Tasks
• Assess salinity– Literature/data review and compilation– Conduct electromagnetic surveys of Red Bluff
Reservoir to Independence Creek• Evaluate management alternatives– Preliminary economic analyses
• Update the Watershed Protection Plan– include practices for controlling salinity levels
Current Status/Next Steps
• Filed HCR 21 and SCR 2 in the Texas Legislature• Applied for a 319 grant through TSSWCB• Developing white paper on background, goals,
and membership• Federal funds?
TSSWCB = Texas State Soil and Water Conservation Board
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