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Comprehensive Stormwater Management Plan Northeast Lino Lakes Drainage Improvement Project WSB Project No. 2929-79 Page 21 6.2.3 Additional BMPs for Consideration of Future Development Additional onsite water quality practices will be encouraged as part of future development, and as part of the Lino Lakes AUAR requirements. The following may be considered, if feasible: Stormwater reuse for irrigation – initial estimates indicate that up to 36 acre-feet of stormwater could be used for irrigation purposes over public open spaces, however the actual amount of volume infiltrated will be defined based on RCWD Rule C.6 Soil amendments – consistent with the RCWD Soil Amendment Guidelines Small-scale BMPs such as tree trenches, raingardens, cisterns, etc. Mechanical separators Media filtration to improve water quality 6.3 Peak Stormwater Runoff Control [RCWD Rule C.7] All stormwater runoff from the area either surface flows directly to Peltier Lake or is conveyed to the lake via the county ditch system (Figure 1, Appendix A). As discussed in Sections 3 and 5, InfoSWMM and HEC-RAS models were developed to evaluate the existing discharge rates entering Peltier Lake. The proposed land uses will result in more impervious surface and higher runoff rates and volumes leaving the CSMP study area and entering Peltier Lake. The regional BMPs will include outlet control structures to regulate the flood releases from the BMPs so they do not impact flood levels on Peltier Lake. 6.3.1 Allowable Peak Discharges Per RCWD Rule C.7, the proposed discharge rates are limited to the existing discharge rates from a site; however, because this area has been identified as a Runoff Sensitive Area, the City will impose a restriction of 0.1 cfs per acre on new private developments for the 100-year peak discharge rate, which is also the same rate requirement the City of Hugo implemented in 2003 as part of their Comprehensive Stormwater Management Plan. This will result in a maximum peak discharge rate from the CSMP area into Peltier Lake of no more than 135 cfs. Table 6-3. Northeast Lino CSMP Allowable Peak Discharge Rates Storm Event Rainfall Depth [in] Discharge to Peltier Lake [cfs] 2-year 24-hour 2.83 68 10-year 24-hour 4.21 133 100-year 24-hour 7.06 135 100-year 10-day 7.20 135 Future development in the CSMP area must not exceed the NOAA Atlas 14 permitted rates to Peltier Lake, as shown in Table 6-3. 6.3.2 Flood Control Storage To meet the proposed discharge rates, a significant amount of land is needed to provide live storage for flood control. As part of the City’s land use practices, the existing wetlands are intended to remain in place where possible and will provide some incidental flood storage capacity. Table 6-4 shows the live storage assumed for flood reduction used in the modeling.