Mill River Subwatershed Information
Municipalities: Boxford,
Georgetown, Newbury, Rowley, Ipswich
Estimated Population: 5696
General Description: The Mill
River is the largest tributary system of the Parker River and includes
much of the Town of Rowley. Land use is primarily undeveloped and
residential, although there are commercial/industrial areas along Route
1 and Route 1A. Additional commercial/industrial development is
occurring along these transportation corridors and more is anticipated.
Rowley’s Watershed Protection and Floodplain District is located
in this subwatershed as are its existing and planned water supply
wellfields. Concerns have been raised recently that the existing well
fields adversely affect baseflow in the Mill River subwatershed.
Governor Dummer Academy is located near the tidal portion of Mill
River. It has a wastewater treatment facility that discharges to an
unnamed tributary of the Mill River. This wastewater treatment facility
recently underwent significant modifications, which will result in
improvements to the quality of the discharge.
Portions of the Georgetown-Rowley State Forest, Willowdale State Forest
and Mill Creek Wildlife Management Area are located in this
subwatershed. All tidal portions of this subwatershed are located in
the Parker River/Essex Bay Area of Critical Environmental Concern. The
Mill River once had an anadromous fishery (blueback herring and
alewives), however the lack of a fish passage facility at the Jewel
Mill (Glen Mills dam) impedes fish movement upstream to their
spawning habitat. Undeveloped land use declined from 8870 acres in 1991
to 8459 acres in 1999, while Residential land use has risen from 1643
acres in 1991 to 2558 acres in 1999.
Land Area: 11494 acres (18 square miles)
Land Use as of 1999: Undeveloped
– 8459 acres (74% of the subwatershed, Forest is 58%)
Residential – 2558 acres
(22% of the subwatershed)
Commercial/Industrial –
484 acres (4% of the subwatershed)
Named Tributaries: Ox Pasture
Brook, Bachelder Brook, Great Swamp Brook, Muddy Brook.
Lakes and Ponds: Wilson Pond,
Upper Mill Pond, Lower Mill Pond, Central Street Pond.
Rapid Watershed Assessment: The
proportion of impervious cover in this subwatershed is estimated to be
5.3%. 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 flow, road runoff,
non-point source pollution and habitat alteration is likely. Additional
impacts are expected with future growth, predicted by recently
completed build-out analysis.
Water Quality Information: The
Department of Environmental Protection Division of Watershed Management
has included the Mill River, Great Swamp Brook, Bachelder Brook and Ox
Pasture Brook in their water quality monitoring programs. The 1994
survey had 4 sampling locations on Mill River (plus 2 near Governor
Dummer), one on Great Swamp Brook, two on Bachelder Brook and two on Ox
Pasture Brook.
The Department of Environmental Protection did not conduct water
quality sampling during the 1999 sampling year. However , biological
monitoring was conducted at one station on Mill River and one station
on Ox Pasture Brook in 1999. The Division of Marine Fisheries Shellfish
Program last monitored water quality in the Mill River in 1994. Due to
high bacteria the Mill River is classified as “Closed” to
shellfishing. The Massachusetts Audubon Society conducted water quality
sampling at 18 sites in this subwatershed as part of its Plum Island
Sound Minibay Project and the Non-Point Source Comprehensive
Implementation Program for the Mill River Subwatershed.
The Parker River Clean Water Association has located 3 sampling sites
in this subwatershed (Jewel Mill, Route 1 at Elm Street, and Fenno
Drive) as part of their volunteer monitoring program. Water quality is
affected in this subwatershed from localized sources of bacteria from
non-point source pollution, failed septic systems, cesspools, domestic
animals and feral animals. Wilson Pond, Lower Mill Pond, and Upper Mill
Pond are included on the Department of Environmental Protection’s
list of waterbodies not in compliance with the state’s surface
water quality standards. They are listed due to the presence of noxious
aquatic plants. Non-point source pollution from agricultural sources to
Mill River has been identified. Some of these sources are in the
process of
being corrected through cooperative efforts by landowners, town and
state and federal agencies.
Reported and identified water quality problems in the vicinity of
Governor Dummer Academy have been addressed through a recent upgrade
and operational improvements to the wastewater treatment facility at
that property. Some sources identified through the Massachusetts
Audubon Society’s Non-Point Source Comprehensive Implementation
Program for the Mill River Subwatershed have been addressed.
Remaining pollution sources can be addressed by continuing to implement
the septic system management program, by implementing best management
practices
for road runoff and stormwater and by seeking to address the failing
septic systems in Rowley Center. The biological assessment conducted by
the DEP at the Mill River site in the vicinity of the Jewel Mill
indicates generally very good aquatic habitat, however the
macroinvertebrate community was rated as being “slightly
impacted”. The biological assessment site on Ox Pasture Brook,
near Fenno Drive, indicated excellent aquatic habitat and the
macroinvertebrate communitywas rated as being non/slightly impacted.
Recommendations: Support the
efforts of the Great Marsh teams, especially with regards to evaluating
the potential of providing passage of anadromous fish to Mill River at
the Jewel Mill or evaluating removal of the dam. Since a significant
proportion of open space is not permanently protected it should be a
priority to work with the Town of Rowley to identify priority areas for
protection. The local open space and recreation committee should be
encouraged to continue to
work closely with the Open Space Committee Network that was recently
created.
Due to the identified water quality problems in this subwatershed the
recommendations from the work conducted by the Department of
Environmental Protection, Division of Watershed Protection and the
Massachusetts Audubon Society should become a priority of the watershed
team. These include outreach on septic system maintenance, inspections
of septic systems in the known problem areas, implement best management
practices related to stormwater control, improve baseflow in the Ox
Pasture Brook tributary, conduct fish community and macroinvertebrate
sampling in the Ox Pasture Brook tributary, evaluate the success of the
septic system maintenance program, provide assistance to the problem
site in the center of town and seek additional low interest loans
through
DEP and others for septic system upgrades.
(Data obtained from the Executive
Office of Environmental Affairs, Massachusetts Watershed Initiative,
2002 Watershed Assessment Report)
Last
update: February 3,
2009