Sponsor: Cottonwood/Grass Creek CRM

The Cottonwood/Grass Creek Watershed Management Plan identified and characterized natural and manmade/influenced conditions/issues relative to all aspects of water resources within the watershed. Plans were then developed to address new surface water storage, irrigation infrastructure, upland stock/wildlife watering, and control of undesirable vegetation.

Features

• Needs analysis and demand projections for irrigation water and assessment of storable flows in the watershed were performed utilizing the existing hydrologic spreadsheet model prepared for the Wind/Bighorn River Basin Plan with corrections and modifications appropriate to the study area and independent checks for reasonableness by interviewing local irrigators and detailed review of available gage data; recommendations were made to develop a StateMod model of the watershed if the project advances to the next level of study
• An integrated spreadsheet model originally developed by SEH for use on dam and reservoir planning studies was further refined and modified for this project; the model was used to compare project alternatives as a basis for screening and as an aid in conceptual design and costing of alternatives

SEH Services

• Compilation of all relevant existing information (including geology, seismotectonics, hydrology, land use, etc.)
• Acquisition of existing and development of new GIS themes; prepare project geodatabase
• Aerial photo interpretation and geologic field reconnaissance of alternative sites
• Feasibility design of dam, spillway, outlet works and other appurtenances at five alternative sites
• Inventory of condition of existing irrigation infrastructure and rehabilitation plan
• Conceptual plans for upland stock/wildlife watering systems
• Cost estimates and economic analyses of alternative new storage projects and other potential watershed improvements
• Identification and characterization of environmental issues and permitting requirements