SALTON SEA MANAGEMENT PROGRAM PHASE I: COSTING TOOL Internal Review Draft February 6, 2018 1
OBJECTIVES Many alternative designs are possible that achieve State Board Stipulated Order Targets Need to estimate costs for a combination of projects A realistic range of costs is needed for planning, as well as to anticipate future funding needs A spreadsheet-based tool, based on prior work, was developed for this purpose 2
PRIOR WORK Performed for the Imperial Irrigation District as part of the Salton Sea Restoration and Renewable Energy Initiative (2015) Performed for the Salton Sea Authority as part of the Funding and Feasibility Action Plan (2016) 3
KEY COMPONENTS FOR COST ESTIMATE Deeper berms (10’) to hold water for overall management in habitat ponds, shallower berms (6’) down-playa for additional habitat (expansion ponds) Assumes vinyl sheet pile for seepage control in a third of the berm length Pump stations and pipelines, to move saline and freshwater to ponds Levees to pass flood flows through rivers, to minimize damage to newly created infrastructure Selected berms are designated as causeways for construction and maintenance Dry dust mitigation in selected areas 4
HIGH LEVEL ASSUMPTIONS All of the ponds would be formed by constructing berms while working in the dry, using traditional earth-moving equipment. Fill for the berm structures would be generated from excavating adjacent soil material directly from the sea-bed and near the berm alignment on the up slope side, and within 200’ of the berm. No artificial islands, channels in ponds, or dredging is proposed as part of these cost estimates. The New River, Alamo, and Whitewater Rivers would flow unimpeded into the Salton Sea with no dam or gravity conveyance into the project. Earthwork items have been included with a 25% contingency. For pumping and backbone infrastructure, a 15% contingency was added to the cost. Dust control areas would be utilized using tillage of the lake bed material with no import or export of materials associated. Each phase of wetlands construction would need to be done at all three river deltas (New, Alamo, and Whitewater) concurrently, estimated at 2 to 3 years each phase. All costs have been prepared in 2017 US Dollars. 5 5
CONSTRUCTION PLANNED IN DRY CONDITIONS 6 6
10-foot High Berm for the Water Management Ponds 7 7
River Flood Control Berm 8
6-foot High Berm for Expansion Ponds 9
Recommend
More recommend
