Date Approved: TBD Date Amended: N/A Amendment Notes: N/A Woonasquatucket River (RI0002007R-10D) Site Description Subwatershed Description Waterbody Woonasquatucket River (RI0002007R-10D) is located within the Narragansett Bay watershed. Woonasquatucket River segment (RI0002007R-10D) flows from the combined sewer overflow (CSO) outfall at Glenbridge Avenue downstream to the confluence with the Moshassuck River near the Washington Street bridge over the Providence River in the City of Providence. The stream corridor is characterized by a mix of commercial and industrial land use. The Rhode Island Department of Environmental Management (RIDEM) water quality classification for the Woonasquatucket River is Class B1{a}, identifying use goals including fish and wildlife habitat, recreational use, industrial processes, and good aesthetic value; however, recreation may be impacted by pathogens from approved wastewater facilities and CSOs. According to RIDEM’s Clean Water Act (CWA) Integrated List of Waterbodies - Appendix A 2014 Index of Waterbodies and Category Listing1, the impairments affecting this water body segment are Mercury, Non- Native Aquatic Plants, Dioxin, PCBs, Benthic-Macroinvertebrate Bioassessments, Dissolved Oxygen, Enterococcus, Copper, Lead, and Zinc. The Woonasquatucket River Fecal Coliform Bacteria and Dissolved Metals Total Maximum Daily Load (TMDL)2 which includes this segment indicates the most prevalent source of the impairments is stormwater runoff and dry and wet weather CSO discharges. Other possible sources include illicit discharges to storm drains, leaking sanitary sewer lines, and wildlife and waterfowl. Figure 2-D shows the subwatershed with the impaired water body segments, the RIDOT maintained roadways, the RIDOT maintained property (catchment area) that is discharging to the waterbody, and outfalls that are discharging to the waterbody. The subwatershed is located the City of Providence, the Town of North Providence, and the City of Cranston. According to 2011 land use data obtained from by Rhode Island Geographic Information System consortium3 (RIGIS), the subwatershed is predominantly high density residential land use with commercial/industrial uses along the Woonasquatucket River and adjacent roadways. According to data obtained from RIGIS, the subwatershed land use is expected to remain constant between 2016 and 2025. The subwatershed is a total of 3,458 acres with 67% impervious cover based on impervious cover data from RIGIS. RIDOT Discharging Area Description Other RIDOT Roadways RIDOT is developing a formal inventory of the roads owned and/or maintained by RIDOT. As part of this SCP evaluation, RIDOT assessed whether their current inventory of roads in this watershed was comprehensive. Preliminary evaluation of the subwatershed indicated that RIDOT potentially 1 RIDEM, May 2015, 2014 Integrated Water Quality Monitoring and Assessment List – Appendix A 2014 Index of Waterbodies and Category Listing. Available at: http://www.dem.ri.gov/programs/benviron/water/quality/pdf/iwqmon14.pdf 2 RIDEM, April 2007, Woonasquatucket River Fecal Coliform Bacteria and Dissolved Metals Total Maximum Daily Load. Available at: http://www.dem.ri.gov/programs/benviron/water/quality/rest/pdfs/woofinal.pdf 3 Rhode Island Department of Environmental Management, Rhode Island Department of Administration, Statewide Planning Program, Photo Science, Inc. http://www.rigis.org/data/rilc11d Stormwater Control Plan for Woonasquatucket River (RI0002007R-10D) Page 1 owns Plainfield Street, Francis Street, and Hartford Avenue, although they are not currently included in RIDOT’s maintained roadways database. Plainfield Street, Francis Street, and Hartford Avenue, are included as RIDOT potentially owned roadways in this subwatershed analysis. RIDOT Roadways Figure 2-D shows the RIDOT maintained and potentially owned roadways in the subwatershed which include: Smith Street (Route 44), High Service Avenue, Plainfield Street (Route 14), Westminster Street, Francis Street, Hartford Avenue (Route 6A), I-95, and Dennis J. Roberts Expressway (Route 6). Of the 3,458 acres in the subwatershed, RIDOT maintains and potentially owns 202 acres of property within the subwatershed, of which 138 acres with 67% impervious cover. The RIDOT direct and indirect discharging areas include the following: RIDOT Roadway Roadway Type ROW Description Adjacent Land Use Drainage System Smith Street two lane roadway with right-of-way (ROW) high density closed drainage sidewalks on both sides width ranging from residential and systems with direct 40- to 50- feet commercial discharge to Woonasquatucket River High Service Avenue two lane roadway with ROW width ranging high density closed drainage sidewalks on both sides from 40- to 50- feet residential and systems with direct commercial discharge to Woonasquatucket River Hartford Avenue two lane roadway with ROW width ranging high density closed drainage (RIDOT potentially sidewalks on both sides from 40- to 50- feet residential and systems with direct owned roadway) commercial discharge to Woonasquatucket River Plainfield Street two lane roadway with ROW width ranging high density closed drainage (RIDOT potentially sidewalks on both sides from 40- to 50- feet residential and systems with direct owned roadway) commercial discharge to Woonasquatucket River Westminster Street three-lane roadway with ROW width ranging high density closed drainage shoulders and sidewalks from 60- to 75- feet residential and systems with direct on either side commercial discharge to Woonasquatucket River Francis Street (RIDOT three-lane roadway with ROW width ranging high density closed drainage potentially owned shoulders and sidewalks from 60- to 75- feet residential and systems with direct roadway) on either side commercial discharge to Woonasquatucket River I-95 divided three (3) lane ROW width ranging commercial and closed drainage highway; three from 150- to 400-feet industrial systems with direct northbound lanes and discharge to three southbound lanes Woonasquatucket with the Exit 23 River interchange Dennis J. Roberts divided three-lane ROW width ranging residential, closed drainage Expressway roadway (three from 180- to 500-feet commercial, and systems with direct eastbound lanes and industrial discharge to three westbound lanes) Woonasquatucket with multiple River interchanges Stormwater Control Plan for Woonasquatucket River (RI0002007R-10D) Page 2 Figures 3-D-1 through 3-D-10 show the approximate catchment areas for each discharge location within the subwatershed. RIDOT used the following data to evaluate drainage patterns and determine catchment areas and discharge locations to the impaired water body segment: drainage, ROW, and plat plans from RIDOT; 2011 U.S. Geological Survey (USGS) Topographic LiDAR: LiDAR for the North East4; and impervious cover data from RIGIS 2011 impervious surfaces data layer5. The plans were used to help delineate RIDOT ROW, determine direction of flow, drainage patterns, and map additional RIDOT structures, pipes, and outfalls. Drainage plans were not readily available for all areas and therefore the direction of flow was assumed based on topography and confirmed during field visits. RIDOT performed a desktop analysis with the combined data above and field visits to investigate areas of question. During site visits, RIDOT determined that the watershed boundary provided by RIDEM for small areas on the northern, western, and eastern side of the subwatershed were not accurately portraying the drainage. RIDOT edited the subwatershed boundary based on the desktop analysis and field confirmation. The boundary alteration resulted in changing the original subwatershed area of 3,437 acres to a final subwatershed area of 3,458 acres (an increase of 21 acres). Figures 3-D-1 thru 3-D-10 show: RIDOT impervious and pervious areas, RIDOT mapped outfalls and catch basins, RIDOT catchment area, and RIDEM-listed impaired water bodies located within the subwatershed. Illicit Discharge Detection and Elimination Priority Outfalls There are 14 mapped RIDOT outfalls within the Woonasquatucket River (RI0002007R-10D) subwatershed. There are no Priority Outfalls located in this subwatershed. Potential Interconnections The desktop review and field visits identified several potential interconnections with municipal or other municipal separate storm sewer systems (MS4s). RIDOT identified locations where RIDOT drainage ties into a municipal drainage system adjacent to their property (outgoing interconnections) and where municipal drainage systems tie into the RIDOT drainage system (incoming interconnections). These interconnections are based on available drainage data and a review of local topography and surface drainage patterns. In cases where interconnections were not identified on drainage plans or visually identified, they were assumed when no RIDOT outfall was identified. Figures 3-D-1 through 3-D-10 shows 14 assumed outgoing interconnections, 1 outgoing interconnection, and 16 incoming interconnections. The assumed owner/operator of the interconnected systems is the municipality the connection lies within. RIDOT is currently implementing multiple efforts to inspect and map the stormwater system. For this watershed, RIDOT has cleaned and inspected catch basins and plans on having survey-grade drainage feature location and inverts by the end of 2017. RIDOT also plans to further inspect these areas while performing additional illicit discharge detection and elimination (IDDE) inspections. If interconnections