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The perimeter of the pond at its waters edge was also recorded using a GPS data logger and the water surface elevation was surveyed. The outlet control elevation was also surveyed at the pond. Field technicians photographed and recorded the type and size of the pond's inlets and outlet. Elevations recorded during the field surveys were referenced to a unique benchmark at the pond. This benchmark was surveyed using GPS and all field elevations were recorded in mean sea level (NAVD 1988 datum using reference monument Round AZ MK MNDOT bolt). The horizontal coordinates were referenced to Ramsey County Coordinates, NAD83 (1996) datum using reference monument Round AG MK MNDOT bolt. 2.6 Stormwater Pond Field Watershed Delineation As part of the data collection process for this assessment, the city staff provided their available storm sewer data and subwatershed delineations for the area. Upon review of the subwatersheds near Silver View Pond, there were multiple areas where there were questions about the accuracy of the subwatershed divides. In some locations the divides passed through what was shown on the mapping as a pond, while in other areas the divides crossed storm sewer systems where it was not likely that There was a break in the grade of the system. Since the MPCA Stormwater Manual calculations for recommended pond capacity are based largely on the size of the direct watershed contributing to a pond. the city authorized Barr to complete a field watershed delineation for Silver View Pond. Using the provided subwatershed divides as a guide, Barr staff completed a field delineation of the Silver View Pond watershed. The held delineation included visiting the watershed and observing the likely flow path of runoff in the area. This entailed noting changes in grade, catch basin inlet points. and surface obstructions that might route or re -direct flow. While several changes were made to the watershed divide for Silver View Pond, many of the changes were relatively minor. The largest change to the watershed was at the property bounded by Long Lake Road, County Road 1, and County Road 10. After Barr's review of the watershed. this property was removed from the watershed tributary to Silver View Pond because no evidence was seen of a way for the water to be conveyed from the property to the South, across County Road 10. The field delineated watershed of previously untreated water that reaches Silver View Pond is 138.5 acres. The total tributary area (treated and untreated) to Silver View Pond is 196.8 acres. Figure 3 shows the field delineated watershed. 11: IvtW 2 V 62 1-W1082 Silver Vic% Pond Asses swerI WorLl'dcs Rcvort SPitcr Victy Pond A doe%