Low Flow Inventory

Nashua River Basin

Observations

During the summer of 1998, DEP staff were unable to conduct benthic macroinvertebrate sampling due to low flow conditions in Boylston Brook near Route 70 in Boylston (3). They estimated that these conditions persisted anywhere from 2 to 17 weeks (1). The Asnebumskit River in Holden also runs dry during low flow periods, although the cause(s) has not been pinpointed (4).

Suspected Causes

Water Withdrawals The installation of the Town of Pepperell’s Jersey Street wellfield coincided with nearb Reedy Meadow Brook periodically running dry, although it had always held water previously (2).

Dam Management No water was released from the Quinapoxet Reservoir in Holden during a DEP field reconnaissance trip in August of 1998. The Quinapoxet River below the reservoir was dry and the first site suitable for benthic macroinvertebrate sampling was 4.5 miles downstream near River Street in Holden. DEP staff recommended optimizing withdrawal practices from the Quinapoxet Reservoir to maintain a minimum flow that mimics the natural flow regime as much as possible in the Quinapoxet River (1).

Interbasin Transfer of Water The Quinapoxet River also suffered streamflow depletion with the completion of the town sewer (4), which now transports wastewater from the Quinapoxet River to the upper Blackstone River .

Consequences

Aquatic Flora and Fauna Benthic macroinvertebrates collected on Trout Brook near Manning Street in Holden for the 1998 Water Quality Assessment Report had fewer caddisflies—a pollution-intolerant and frequently flow-sensitive group— and more chironomids—a pollution-tolerant and flow-insensitive group— than the same location in previous years. The brook was dry on at least four dates in August and September of 1999, but was still listed as a reference station, or unimpacted site (1).

References & Resources

1. Weinstein, Mollie J., Kennedy, Laurie E., and Jane Colonna-Romano. January 2001. Nashua River Basin 1998 Water Quality Assessment Report, Report Number 81-AC-3, DWM Control Number 46.0. MA DEP, Bureau of Resource Management, Divison of Watershed Management.
2. Dave Armstrong, USGS. Personal communication, February 2002.
3. Duval, Brian. July 5, 2001 . Nonpoint Source Action Strategy, Nashua River Basin . MA DEP.
4. JoAnne Carr, Watershed Initiative Team Leader, Nashua River Basin . Personal communication March, 2002.
5. USGS real-time stream gage data on the North Nashua River at Fitchburg.
6. USGS real-time stream gage data for the Stillwater River near Sterling.
7. USGS real-time stream gage data for the Quinapoxet River at Canada Mills near Holden.
8. USGS real-time stream gage data for the Squannacook River near West Groton.
9. USGS real-time stream gage data for the Nashua River at East Pepperell.