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City of Gem Lake Comprehensive Plan GEMLK 140643 Page 62 7.2.2.3 Wet Weather Analysis An analysis of the existing sewer system was performed with a wet weather peaking factor. Wet weather modeling is performed to account for typical sanitary sewer flow with the addition of inflow and infiltration (I/I) into the sanitary system. A wet weather factor of 4 was applied to the model, based on MCES allowable peaking factors. Figure 7-3 shows the existing system d/D ratios with wet weather flow rates. The modeling resulted in a system with multiple existing pipes at capacity, with d/D ratios greater than 0.6. 7.2.2.4 Future System Model Analysis Two scenarios were modeled, dry weather and wet weather, similar to the existing conditions modeling, using the same sanitary loading rates as listed in Table 7.5. As in existing modeling, the flow rate per future land use type was multiplied by parcel acres to determine proposed waste water flow rates for each development area. An analysis similar to what was done for existing conditions modeling was performed for proposed development conditions using future land use. The City of Gem Lake has phased future sewer connections, shown in Figure 7-4. Two stages are anticipated and noted in the following figures and tables. Table 7-5 shows flow rates from future planned connection areas using the future land use. Table 7-5 – Current and Proposed Wastewater Discharge (MGD) into MCES Interceptors/Community Connections Year Destination Population Houses Employment PWWF [MGD] (Design Flow, PF = 4) Capacity [MGD] 2020 Unsewered 280 106 160 N/A N/A MCES Interceptor 7122 (North East District) 175 82 0 0.052 0.54 MCES Interceptor 7122 (East District) 25 12 0 0.004 0.61 MCES Interceptor 7122 (3800 Scheuneman Rd.) 0 0 15 0.004 N/A MCES Interceptor 7122 (3734 Scheuneman Rd.) 0 0 15 0.004 N/A MCES Interceptor 1-VH- 423 (South District S2) 0 0 130 0.028 0.49