Low Flow Inventory

Narragansett Bay Basin

Suspected Causes

Water Withdrawals A local resident observed that water levels in Rocky Run, a tributary to the Palmer River in Rehoboth, were depleted by a local contractor who routinely filled his truck with water directly from the river to control dust at construction sites during summer and fall of 2001. The resident stated that the water level in this reach of Rocky Run was noticeably lowered by this activity. In addition to the ongoing drought conditions, this repeated pumping resulted in water levels two to three feet lower than usual for late summer (1).

Interbasin Transfer of Water The Palmer River from the confluence of the East and West Branches of the Palmer River to Route 6 in Rehoboth suffers from depleted streamflows due to an interbasin transfer of water out of Shad Factory Pond (2). This water is transferred into the Kickemuit Reservoir in Warren, Rhode Island where the Bristol County Water Authority withdraws water for Bristol County, Rhode Island. The Bristol County Water Authority has not metered its withdrawals from Shad Factory Pond, so the actual amount of water removed from the Palmer River Basin is unknown. Additionally, the Bristol County Water Authority has not managed withdrawals and releases from Shad Factory Pond to maintain adequate stream flow to support the aquatic community (see Aquatic Flora and Fauna below) (3).

Consequences

Aquatic Flora and Fauna Fish passage into and out of Shad Factory Pond is currently impeded by both the dam structure itself and the lack of stream flow. A fish passage structure on the dam has been proposed to allow shad to migrate into and out of the pond, but it is only a feasible alternative if enough water is released over the structure to allow fish to pass. Low flows are likely to be especially problematic on this section of the Palmer River during early fall, when stream flows are naturally lowest and adult shad need sufficient flow to navigate back to the ocean. However, the river could experience low flows at other important times of the year due to water withdrawals or operations of the control structure (3).

References & Resources
1) James Pereira, Rehoboth resident. Email to Russ Cohen, Riverways River Advocate, September 2001.
2) Brownell, Jeffrey. June 27, 2001. Nonpoint Source Action Strategy, Mt. Hope/Narragansett Bay Basin. MA DEP.
3) Russ Cohen, Riverways River Advocate. Memo to Andrea Langhouser, Ten-Mile/Narragansett Bay Watershed Initiative Team Leader. April 2002.