MS4 Mapping and Drainage Study Support

Sherwood, AR., contracted FTN to assist with mapping the City’s Municipal Separate Storm Sewer System (MS4) as required by the city’s MS4 General Permit and to gather information to be used for additional drainage studies. The MS4 map must include the locations of all outfalls from the MS4 and the names and locations of surface waters that receive discharges from those outfalls. The map must also include the entire MS4 system, including inlet and outlet points and connectivity (e.g., catch basins, pipes, ditches, and public and private stormwater facilities).

FTN prepared a digital base map of the City that included information relative to the MS4 map. The digital map also included development of a grid system (coordinated with their existing sanitary sewer system mapping) to assist in the location of MS4 system components during the field identification and verification stage. A GIS database was used to capture the pertinent data required for the MS4 map as well as to allow for additional data to be entered for use in creating an inventory of the City’s storm drainage infrastructure and to support future drainage project needs.

FTN reviewed the City’s files to identify and index the available data relative to the MS4 map. All of the available data were entered into the database and areas of data deficiencies were identified.