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RIDOT: Buckeye Brook Stormwater Basin Rehab Underway

[CREDIT: Buckeye Brook Coalition] Buckeye Brook, one of 17 Warwick waters on the DEM's Impaired Waters List, has the longest list of impairments among local water bodies.

[CREDIT: Buckeye Brook Coalition] Buckeye Brook, one of 17 Warwick waters on the DEM's Impaired Waters List, has the longest list of impairments among local water bodies.
[CREDIT: Buckeye Brook Coalition] Buckeye Brook, one of 17 Warwick waters on the DEM’s Impaired Waters List, has the longest list of impairments among local water bodies.
WARWICK, RI — RIDOT is replacing two 1990s era stormwater management holding basins that discharge into Buckeye Brook, north of the Knights of Columbus Hall on Sandy Lane and Warwick Ave.,  in a $598,500 project started last week.
During construction, traffic on Old Warwick Avenue will be detoured via Warwick Avenue, but will remain open for pedestrian traffic. Also, intermittent weekday daytime lane closures are possible on Warwick Avenue in the project area. The project is expected to be finished by mid-November.
The project is expected to finish by the end of the year.

According to an announcement from RIDOT, the agency will rebuild and expand the two water quality basins on the north and south sides of the brook. The basins have become overgrown with vegetation and have reduced capacity from accumulated sediment and debris from stormwater runoff. The new ponds will accept diverted stormwater and filter it through soil and plant materials to remove pollutants before it discharges into the brook.

The new system will capture the first inch of rainfall, also known as the “first flush,” which typically contains the most pollutants and sediment. The project captures stormwater from a 31-acre watershed area and will effectively reduce 9.9 acres worth of runoff from paved, also known as impervious, surfaces.
“This project is but one of dozens of stormwater improvements we’re doing over a 10-year period to reduce the impact of stormwater pollution on our rivers, lakes, streams and beautiful Narragansett Bay,” said RIDOT Director Peter Alviti, Jr.
“These are the types of watershed restoration and stormwater improvement projects which we advocate for and support,” said Michael Zarum, president of the Buckeye Brook Coalition, which is the RI Rivers Council’s official State Designated Local Watershed Council for the Buckeye Brook and its watershed. “This project for stormwater flowing into Buckeye Brook absolutely meets goals for new green infrastructure, design requirements in the latest edition of the RI State Stormwater Design Manual, and stormwater best management practices.”
The project is funded as part of RIDOT’s 10-year, $110 million commitment to come into compliance with a 2015 consent decree with the Environmental Protection Agency (EPA). It mandates that RIDOT gets into compliance by treating pollutants in stormwater from all state roads and keep the whole system clean and maintained. RIDOT is responsible for a massive and complex system of catch basins and pipes that exists under Rhode Island’s road network – about 35,000 structures – that haven’t been adequately maintained for years.
According to the Buckeye Brook Coalition, the following improvements will be made:
  • Expansion of northern retention basin capacity from 15,000 CF (cubic feet)  to 23,185 CF
  • Expansion of the southern retention basin capacity from 16,800 CF  to 24,360 CF
  • Conversion of the southern retention basin into a bio-retention basin with an under drain to provide higher levels of stormwater treatment which will improve the filtering out of pollutants transported in the collected stormwater,  by a process where the collected stormwaters will be filtered through natural soils, natural plants  and organic materials, and geo-textile materials which filter out and remove pollutants before the stormwaters flow into Buckeye Brook, thereby reaching goals to discharge cleaner stormwater into Buckeye Brook.
  • Installation of  two (2) pretreatment units will include hydrodynamic separators upstream of the stormwater bio-retention basin and will further increase water quality treatment by including these  Best Management Practices (BMP’s) to extend the viability of the reconstructed stormwater basins (there is currently no pretreatment for the existing wet ponds).
  • Removal and replacement of the existing chain link fence and guardrail next to the basins.
  • Installation of new corrugated plastic pipe outfalls to Buckeye Brook with rip-rap scour and erosion control protection pads at the reinforced concrete pipe’s flared ends (RCP’s flared ends).

The existing wetlands on site will not be altered as part of the proposed project.  However, there will be work that falls within the 100-foot riverbank wetland for Buckeye Brook, the 50-foot perimeter wetland for the wooded swamp and the two Areas Subject to Storm Flowage (ASSF).  Sediment and erosion controls have already been put in place at the construction site.

The project will also lower the risk of flooding in the area by providing additional watershed storage volume and will reduce peak rates of flow to Buckeye Brook.

Rob Borkowski
Author: Rob Borkowski

Rob has worked as reporter and editor for several publications, including The Kent County Daily Times and Coventry Courier, before working for Gatehouse in MA then moving home with Patch Media. Now he's publisher and editor of WarwickPost.com. Contact him at [email protected] with tips, press releases, advertising inquiries, and concerns.

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