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Torres Martinez Wetland Project

Project: White Water River Wetland
Client: Torres Martinez Band of Desert Cahuilla Indians
Size: 85 Acres
Duration: 2 Years
Funding: $680,000

Services Provided:

  • Scoping & Planning
  • Water Acquisition
  • Financing
  • Permitting
  • Data Development
  • Design
  • Construction Management
  • Construction
  • Utilization
  • Vegetation
  • Operation & Maintenance

View Presentation on Wetland Water Treatement


Summary

aerial view

The Torres Martinez Band of Desert Cahuilla Indians occupies land at the north margin of the Salton Sea. As much of the land owned by the Tribe is submerged by the Salton Sea, the Tribe has great interest in uses of that land, and stabilization of its sediments, when the shoreline of the Sea retreats due to declining inflows of water. Support from the EPA and the California Department of Water Resources has allowed the Tribe to develop a wetland complex at the mouth of the Whitewater River where it enters the Sea. Agrarian was retained to develop conceptual plans, pre-design data, final designs, and construction of a treatment and a habitat wetland. Agrarian developed soil, water, and topographic data, and managed all areas of permitting including a wetland delineation and easements with adjacent landowners and water authorities.

The project has 10 acres developed as a subsurface vertical flow wetland with the goal of treating Whitewater River flows for sediments, nutrients, and pesticide/herbicide residues. The treated water is introduced into a 12-acre freshwater habitat wetland, and then blended with Salton Sea water to create an additional 63 acres of shallow saline habitat for shorebirds. The project thus has three features: water treatment, fresh and brackish habitat wetlands, and surface stabilization of sediments. As a pilot project, it allows the Tribe to gain experience with wetland development, and to establish reasonable costs for treating a large number of acres in a similar fashion when it becomes necessary. Agrarian's cost-effective and agriculturally orientated approach to this project was welcomed by the Tribe, which had feared spending all the grant money on engineering alone. Using NRCS specifications, Agrarian was able to keep construction costs low, allowing for a much larger project than had been anticipated.

dikes

This dike separates two wetland cells. It was created with a pushcat and a scraper in primarily sand soils.

treatment wetland vegetation


Treatment wetland cells treat water using vegetation up take of nutrients, and soil filtration.

habitat islands

Islands and snags create habitat features for nesting, resting, and other bird activity.

vegetated islands

The construction activities left existing vegetation in place to allow for additional habitat features.


Site Photos