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I I I I I I I I I I I I I I I I I I I ~ - 30 - the structure's location, it is, however, susceptible to damage should the Four Seasons Pond Dam immediately upstream wash out. Blockage of this structure with debris contributes to the overbank;flooding problem started by the Four Seasons Pond Dam. Because of the backwater, water forced out of the channel by the dam cannot return and there is considerable flood damage potential to the Four Seasons shopping center. Villaqe Road to Lincoln Avenue Downstream of Village Road crossing there is considerable flood damage potential from the overbank flooding discussed in the previous section. The east bank channel, while adequate for capacity, could be improved or strengthened to provide more protection. The sharp bend going into the pond below Village Road crossing is subject to erosion and water could leave the bank at this point. A new bridge is being proposed by the town located at an ex- tended Adams Street crossing. Engineering designs were not available at the time of this report to analyze the structure. To insure there is no encroachment into the floodway by the bridge, the east approach should be raised so that the under- clearance is at least 2 feet above the flood level. Immediately below the existing pedestrian bridge, which is subject to damages or washout under both IRF and SPF flood conditions, the east bank of the river channel is below the flood level and floodwaters will leave the channel and cause overbank flooding at this point. The flood will cause sheet flow (depth of flood generally less than 2 feet) through the town essentially paralleling Highway 9. This flooding is com- pounded by the Lincoln Avenue crossing if plugged with debris. This structure has the capability, however, of passing the IRF if kept open and free of any obstructions or debris. The crossing consists of three 54" diameter iron pipe culverts. The condition of this crossing is not as good as Village Road and should be one of the first replaced with an adequate cross- ing structure. It is located immediately below Sawmill Gulch where it joins the Blue River and there is a flood potential hazard from that source. The proxi~ity of the drugstore re- cently constructed at the corner of the Blue River and Lincoln Avenue on the upstream makes this an important structure to replace. ~ Leonard Rice Consultrng Water Engineers. tne.