Save the El Dorado Canal v. El Dorado Irrigation District CA3

BACKGROUND

The District, a public water agency located in El Dorado County, operates a water system that relies exclusively on surface water to meet its potable water demand. The system contains more than 1,250 miles of pipe and 27 miles of earthen ditches connecting various water facilities, including five water treatment plants (WTP’s). One of the District’s main water conveyance features is the Upper Main Ditch, a roughly three-mile stretch of open and unlined ditch connecting the District’s Forebay Reservoir to the Reservoir 1 WTP. The Proposed Project The District proposed to convert the Upper Main Ditch into a buried 42-inch pipeline that would span the entirety of the existing ditch. Several reasons were advanced for the conversion; foremost among these was water conservation. As the draft EIR explains, citing a 2017 study, the open and unlined nature of the Upper Main Ditch results in “11-percent to 33-percent” of the water conveyed through the ditch being lost “due to seepage and evapotranspiration” each year, “depending on flow rates and annual diversions.” Citing data from 2009 to 2015, the draft EIR estimates “minimum water savings of approximately 1,350 acre-feet per…