SU0004095 - Laserfiche WebLink

Home Browse Search

RECLAIAIATIONPLAN—SOLARI PIT 2002 George Reed,Inc. Page 2 I. DESCRIPTION OF ENVIRONMENTAL SETTING continued C. Hydrology The most recent incident of extreme precipitation and flooding along the Central Valley's rivers occurred in 1997. None of the parcels within or adjacent to the project area were inundated or subjected to overflow from the South bank of the Mokelumne River (with an existing elevation variance from f84' to t87'). Recent discussions with the San Joaquin County Department of Public Works indicate the proposed project is outside the floodplain. During extreme precipitation and/or high river flows, normal flooding occurs along the North bank, with an existing elevation variance of f80' to ±82'. As a precautionary measure to insure against any possible flooding of reclaimed orchards,the applicant proposes to construct a berm with a minimum top elevation of 86' on the river's South bank. The berm will have a top width of±12' with a 2:1 slope, and will be positioned adjacent to the excavation perimeter outside the riparian tree drip line. Additionally, the berm will continue along the Western boundary line of the property with a uniform top elevation of X86', thus preventing any potential flooding attributable to adjacent low lands to the West. Construction of the berm will be completed prior to the start of excavation. Berm details are shown on the Reclamation Site Plan map. Excavation depths will not exceed f25', therefore penetration of groundwater situated at f 130' will not occur. (Ref: San Joaquin County Flood Control &Water Conservation District—Groundwater Report, Fall 1998). Waste discharge is not applicable to this application. D. Soil Assessment Engineered drawings, based on boring logs, indicate an abundance of topsoil to complete reclamation of disturbed areas back to farming capability. The quarry area is located entirely within Vina and Columbia soils. The U.S. Soil Conservation Service has stated that the Vina and Columbia soils are Prime Farmland. These soils are generally used for irrigated cropland, orchards and vineyards. They are well suited for irrigated row, field, orchard, and vine crops, and have few limitations. Permeability of the Vina soil is considered moderate, and Columbia soils are moderately rapid (2.0 — 6.0 in/hr). Runoff is considered slow and the hazard of water erosion is slight. Underlying these soils are sand, gravel, and rock to be excavated. Replacement of the "top soils" for reclamation has been successful as can be seen on the adjacent parcel, where 100 (previously excavated) acres have been reclaimed to a walnut orchard. The operator has successfully reclaimed 250 acres of excavated land back to walnut and almond orchards with annual yields equal to, and sometimes exceeding, the County average in production. l E. Vegetation I Wildlife All but 20 acres of open land (where excavation will commence) is currently walnut orchards and has been farmed for many years. The only vegetation and 1 or wildlife of concern are located adjacent to the project area along the riparian corridor of the Mokelumne River, which will not be disturbed. Pursuant to Section 9-1510.5 of the San Joaquin County Development Title, excavation or other activity will be limited to a minimum of 100' from the mean high water level of the natural bank and 25' outside the drip line of any existing trees to provide a natural open area for the riparian habitat. , No trees will be harmed or removed. There are no rare,threatened, or endangered species of wildlife and/or plants identified within the project site (Reference EIR-90-8). Noxious weeds are non-existent due to the many years of farming within the project area. F. In-Stream Mining In-stream mining is not applicable to this project.