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Exhibit A- Engineer’s Services <br /> <br />DTSB Stormwater Plan - Scope of Services <br /> <br />Page 14 of 17 <br /> (Exhibit A- Engineer’s Services) <br />o To serve City R/W only with R/W estimated based on current GIS layers (identified <br />as “Base Condition”) <br />o Base Condition modified to include existing levels of development contributing from <br />outside the R/W (identified as “Improved Base Condition”) <br />o Improved Base Condition modified to significant levels of redevelopment (90% <br />impervious typical) contributing at known targeted development parcels (identified <br />as “Targeted Development Condition”). The location and extent of these targeted <br />development parcels will be confirmed by the City prior to the initiation of work, but <br />generally include the following identities: <br /> Madison Lifestyle Center <br /> River Glen <br /> Shared Housing Authority Parcels <br /> SB Tribune Building <br /> Morris Performing Arts Center Garage <br /> Diamond View <br /> Studebaker <br />o Targeted Development Condition modified to reflect full development of DTSB <br />service area at approximate 90% level, with some limited exceptions developed to <br />approximately 50% level (identified as the “Full Development Condition). <br />- Assume that proposed sewers are to be sized to accommodate a 10% Annual Exceedance <br />Probability (10-year storm) using the latest NOAA Atlas 14 rainfall data for various storm <br />durations. If possible, the proposed storm sewer should not surcharge for any storm <br />duration analyzed (ex. 1-hour event, 3-hour event, etc.). <br />- Service areas will generally be delineated in such a way that City R/W is separated from the <br />areas outside the R/W for maximum flexibility in analysis. <br />- No detention facilities are to be considered in the above analyses for the potential reduction <br />in peak flows to the proposed storm sewer network. <br />- Develop a cost-basis function to develop anticipated costs for proposed storm sewer <br />improvements to include the following conceptual elements: <br />o Replacement of at least one lane (12-feet) of asphalt pavement due to sewer <br />mainline installation <br />o Replacement of curb line along proposed alignment <br />o Replacement of sidewalk on one side of the street <br />o Pipe excavation quantity estimate functions, based on proposed sewer depth <br />o Pipe backfill quantity estimate functions, based on proposed sewer depth <br />o Pipe material cost for various proposed sizes. <br />o Allowance for curb inlet construction/tie ins at an assumed interval (ex. Every 50 or <br />100-feet) <br />- Prepare preliminary cost estimates for the four scenarios noted above.