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7550 MERIDIAN CIR N, SUITE 120 | MAPLE GROVE, MN 55369 PAGE 6 OF 8 Table 3. Calculation of Estimated Land Value Change Item Value Area of Parcels Adjacent to RCD 4 65.9 Acres Existing ROW Area 6.45 Acres Reduced ROW Area 1.7 Acres Total EMV (Per Ramsey County parcel data) $29,026,800 Per Acre EMV (based on non-ROW land) $488,255 Decrease in ROW Area (acres) 4.75 Increase in EMV based on reduced ROW $2,319,214 EMV of remaining ROW area $830,034 UPSTREAM FLOODPLAIN REDUCTION Under existing conditions, the unnamed detention pond upstream of County Road C floods to an elevation of 917.22 (NAVD 88)3 during a 100-year storm event. This flood elevation corresponds to an flooded area of 5.05 acres, which inundates both residential lots and road ROW. The proposed project lowers this flooding elevation to 916.94 (NAVD 88), which corresponds to an area of 4.86 acres, or a 0.19-acre decrease. The benefit of the flood reduction goes beyond the decrease in floodplain, as more frequent rainfall events will also have reduced peak elevations. One method to determine the value of the upstream flood reduction provided by the proposed project is to determine the cost of an alternative project required to achieve a similar level of flood reduction. The alternative project consists of excavating next to the pond to create additional storage within the basin. Using the District Wide Modeling Program (DWMP), we determined that creating approximately 3 acre-feet of additional storage achieves a similar reduction in flooding to the proposed project. Table 4 displays a cost estimate for the alternative project.4 Table 4. Cost Estimate for the Alternative Project (Pond Excavation) Item Unit Unit cost Quantity Cost Mobilization LS $15,000 1 $15,000 Common Excavation and Haul-Off CY $10 5,000 $50,000 Erosion Control and Seeding LS $15,000 1 $15,000 Construction Cost $80,000 Contingency (25%) $20,000 Engineering (20%) $16,000 Total Cost $116,000 3 All elevations reported in this memo are NAVD 88, unless otherwise specified 4 Assumed that no maintenance costs over a 100-year period to maintain the additional flood storage.