Draft Environmental Impact Report - East Bay Municipal Utility District

Dingee Pressure Zone Improvement Project - Estates Reservoir Replacement ProjectWater Distribution Facilities - Initial Studye) Create or contribute runoffwater which would exceedthe capacity of existing orplanned stormwater drainagesystems to control?f) Otherwise substantiallydegrade water quality?g) Place housing within a 100-year flood plain, as mappedon a federal Flood HazardBoundary or Flood InsuranceRate Map or other floodhazard delineation map?h) Place within a 100-yearflood plain structures whichwould impede or redirectflood flows?i) Expose people or structuresto a significant risk of loss,injury or death involvingflooding, including floodingas a result of the failure of alevee or dam?j) Inundation by seiche,PotentiallySignificantImpactLess ThanSignificant WithMitigationIncorporatedLess ThanSignificantImpactNoImpact tsunami, or mudflow?a) The EBMUD water distribution system/facilities are designed, constructed, operated and maintained to conformto state and federal requirements for water treatment and discharge, thus no impacts to water treatment anddischarge are anticipated and no further analysis and/or mitigation measures are proposed.b) The project would not deplete groundwater supplies or recharge, because the permeable site surface willincrease, with a commensurate increase in infiltration (from precipitation), groundwater and recharge. Nodrinking water wells are located in the vicinity of the project site and thus no impacts to groundwater areanticipated and no further analysis and/or mitigation measures are proposed.c) Natural drainage features at the project site will not be altered, but an increase in percolation and water collectionat the proposed valve pit (in the reservoir bowl) is anticipated once the concrete reservoir lining is removed. Anyincreased water will easily percolate through the soil downstream into the existing culverted creek. Drainagepatterns may be temporarily disrupted during construction. No impacts to the existing drainage system areanticipated and no further analysis and/or mitigation measures are proposed.d) Existing drainage patterns will be utilized (c., above).e&f) The project will not increase storm water run-off. New and modified drainage located within the reservoir basinwill tie into the existing storm drainage located at both sites, thus the project will not substantially degradeexisting groundwater water quality, and thus no impacts to storm water are anticipated, and no further analysisand/or mitigation measures are proposed.g&j) The project sites are not located within a 100-year flood plain. The project would eliminate the potential forflooding as a result of the failure of a dam.sb09_003.doc 22 12/10/08