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<br />Therefore the volume control was based on the runoff from the 0.8" event for only <br />that portion. <br /> <br />Table 2 compares the pond characteristics for the southeast and southwest laMotte <br />Park ponds. <br /> <br />Location Drawdown Excavation Pond Irrigation Outiet Required <br /> Volume Elevations Depth Bottom Time Elevation Volume <br /> (ac-ft) (ft) (weeks) (ac-ft) <br />Southwest 4.0 15 4 3.0 <br /> 893-897 889 897 <br />Southeast 2.2 21 2 2.9 <br /> <br />Table 2 <br /> <br />The required volume accounts for the 2.9 ac-ft of infiltration volume that is needed for <br />the downtown redevelopment and in the case of the southwest pond, it accounts for <br />the existing laMotte Park impervious (parking lot and skate park). Since the <br />southwest pond essentially expands to include the existing pond, the additional <br />volume needed for the parking lot and skate park needs to also be provided in the <br />pond. <br /> <br />The drawdown volume would be utilized for irrigation and for compliance with RCWD <br />volume requirements. An additional 4 feet of excavation below the 893 contour is <br />needed to allow for sedimentation and to prevent cavitation in the pump works. The <br />excavation depth reflects the depth below the existing ground elevation that is <br />needed. <br /> <br />The irrigation time reflects the length of time that the adjacent park can be irrigated <br />with the drawdown volume. This is based on the assumption that the entire park, <br />approximately 12 acres (including the green space adjacent to the ballfields and <br />soccer fieldS) would be irrigated at a rate of 1 inch/week. If only the ballfields were <br />irrigated the volume is sufficient for approximately 5 weeks for the southwest pond <br />and 3 weeks for the southeast pond. <br /> <br />Table 3 summarizes the drawbacks and benefits for each of the pond options. <br /> <br />Page2of4 <br />