Penn
Brook Subwatershed
Information
Municipalities: Boxford,
Georgetown
Estimated Population: 2014
General Description: The Penn
Brook subwatershed begins in Boxford at the watershed divide between
the Parker River watershed and the Ipswich River watershed. A small
stream flows behind the Spofford Pond School, around the Boxford
sanitary landfill to Baldpate pond. Penn Brook then begins at the
outlet of Baldpate Pond through wetland areas until it reaches
Georgetown town center. It joins the Parker River downstream of
Pentucket Pond. Flooding is a concern within the area of the
subwatershed that is influenced by the Georgetown town center.
An anadromous fish run once existed in Penn Brook with alewives
spawning in Baldpate Pond. Alewives can no longer reach Baldpate Pond
due to impassable culverts at Central Street (Route 97) and at a rail
bed easement further upstream. Boxford State Forest and Georgetown
Rowley State Forest comprise some of the protected open space in this
watershed, together with a few privately held protected parcels. The
Undeveloped land use category has declined from 1905 acres in 1991 to
1793 acres in 1999. Residential land use increased from 567 acres in
1991 to 793 acres in 1999.
Acres/Square Miles: 2661
acres/4.2 square miles
Land Use as of 1999:
Undeveloped – 1793 acres (67% of the subwatershed, Forest is 55%)
Residential: 793 acres
(30% of the subwatershed)
Commercial/Industrial: 75
acres (3% of the subwatershed)
Named Tributaries: Bulford Brook
Lakes and Ponds: Little
Baldpate, Baldpate Pond
Rapid Watershed Assessment: The
proportion of impervious cover in this subwatershed is estimated to be
4.5%. The water quality would be expected to be of high quality. While
a comprehensive survey has not been done, one would expect to find
excellent habitat, diverse communities, and a stable stream channel.
However, some localized impacts from summer low flows, road runoff,
non-point source pollution and habitat alteration is likely. Impacts
are expected
with future growth, predicted by recently completed development
build-out analysis.
Water Quality Information: Monitoring
conducted by the Department of Environmental Protection since 1975
indicates that Penn Brook is impacted by non-point source pollution.
Monitoring was conducted at two stations on Bulford Brook and two
stations on Penn Brook in 1978 as well as three stations on Penn Brook
in 1994. Data from these stations indicate that Penn Brook suffers from
low dissolved oxygen and relatively high concentrations of nutrients
and fecal coliform bacteria.
A biological assessment was conducted in the vicinity of Parsonage
Street in the summer of 1999. This survey, conducted in a 20-meter
section of Penn Brook, revealed that the aquatic habitat in this area
is severely impaired from habitat disturbance, while the
macroinvertebrate survey indicates an absence of gross levels of
organic pollution. Therefore, erosion, sedimentation, removal of
riparian vegetation and localized sources of non-point source pollution
are likely the
primary causes of the habitat impairment.
The Department of Environmental Management Lakes and Ponds Program
conducted a survey of Baldpate Pond in 1998. The Department of
Environmental Protection did a previous survey in 1981. There have been
slight changes in water quality between the surveys, however land use
change (from forest to low density residential) at the southern side of
the pond will likely influence the future water quality. The Parker
River Clean Water Association has a monitoring station located on Penn
Brook at Georgetown High School as part of their monthly volunteer
water quality monitoring program.
Recommendations: Continue to
work with the Boxford Open Space Committee and Georgetown Open Space
Committee to establish joint open space protection projects. Work with
the Mass. Highway Department, Georgetown Highway Department and
Massachusetts Electric to identify ways to eliminate obstructions to
fish passage at Penn Brook. A shoreline survey and aquatic habitat
survey should be conducted in this subwatershed. Outreach and volunteer
efforts to address improper yard waste disposal, riparian buffer
disturbance, non-point source pollution and littering of the stream is
needed here.
Work with local groups to establish a link between Boxford State Forest
and Georgetown-Rowley State Forest, possibly by establishing a
protected greenway along Penn Brook. Need to locate, inventory and
certify vernal pools.
(Data obtained from the Executive
Office of Environmental Affairs, Massachusetts Watershed Initiative,
2002 Watershed Assessment Report)