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Alamo River Shallow Saline Habitat

Project: Alamo River Shallow Habitat
Client: Bureau of Reclamation
Size: 103 Acres
Duration: 7 Years
Funding: $970,000

Services Provided:

  • Scoping & Planning
  • Property Acquisition
  • Permitting
  • Data Development
  • Design
  • Economic Study
  • Construction Management
  • Construction
  • Utilization
  • Operation & Maintenance
  • Decommissioning


Alamo aerial

The Salton Sea Science Office (United States Geological Survey, USGS) approached Agrarian to develop plans for a shallow habitat demonstration project at the Salton Sea, using concepts that had been advanced at a workshop on shallow habitat that Agrarian had organized early in 2004. Bureau of Reclamation funds were available for projects that would address uses for a reject stream of water from a proposed desalination plant. Agrarian designed, constructed, and is operating this 100-acre shallow saline wetland habitat project in collaboration with the Science Office near the mouth of the Alamo River at the south end of the Salton Sea. The project involves pumping water both from the Salton Sea and from the Alamo River to create a blended brackish water of about 20 ppt. The four ponds in the series concentrate the brine evaporatively, up to a final concentration of about 80 ppt.

This project was designed to test the viability of low-cost construction techniques for developing large numbers of acres of such habitat. The work involved berm construction in saturated clay soils which are highly fractured. Other challenges included excavation of a trench to the Salton Sea for brine delivery, necessitating a gravel fish screen to prevent disturbance to pupfish. The pipeline delivering the water to the project was 8 inch PVC, buried to a depth of three feet for a distance of 8600 feet.

The Science Office is using the site for extensive observations regarding bird use in the four ponds. They are also conducting sediment and water evaluations to determine if any toxicity issues exist that would need to be addressed if this habitat were to be expanded. Shoreline land developed in this way would serve the dual purpose of providing habitat for shorebirds as well as stabilizing exposed sea-bed sediments.

birds on pondsunset pond

Birds found these ponds within a matter of days. It is not uncommon to see several thousand birds feeding or resting in one of these 25-acre ponds.

excavator in mud

Construction of one of the berms took place in saturated soils. All berms were built with native material that was not removed from the site. Drying and compaction took place in situ.

 

pond islands egrets

Islands in the ponds provide nesting and resting habitat for birds. These egrets are enjoying the small fish that are introduced into the ponds with water pumped from the Alamo River.


Aerial Photos


Construction Photos