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(gfe) NONPOINT SOIREE SICEESS STORY

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McQuesten Brook Restoration Protects Native Brook Trout

Waterbody Improved McQuesten Brook runs through highly urbanized areas. Despite

the stressors associated with that setting, the brook hosts a
robust population of native eastern brook trout. Low dissolved oxygen (DO) levels and barriers
to fish passage threatened the survivability of the trout, and McQuesten Brook was added to the
Clean Water Act (CWA) section 303(d) list of impaired waters for DO in 2010. In response, the
New Hampshire Rivers Council (Council) coordinated implementation efforts recommended in
the McQuesten Brook Geomorphic Assessment and Watershed Restoration Plan. Actions included
bioengineered bank stabilization, floodplain restoration, stream crossing upgrades and stream
daylighting that restored natural channel geometry, function, and DO levels. As a result, the New
Hampshire Department of Environmental Services (NHDES) removed a segment of McQuesten
Brook from the 2018 CWA section 303(d) list of impaired waters for DO.

Problem

in 2010, NHDES listed a segment of McQuesten Brook
(assessment unit NHRIV700060803-16), a tributary
to the Merrimack River, located in Bedford and
Manchester, New Hampshire, for failure to support
aquatic life integrity due to insufficient DO concentra-
tion. The brook did not meet the state standard of
5.0 milligrams per liter (mg/L). A sequence of open
and closed channels and four fish passage barriers
restricted the movement of brook trout and contrib-
uted to the DO impairment in this highly urbanized,

564-acre watershed (Figure 1).

Story Highlights

NHDES awarded the Council a CWA Section 319
Watershed Assistance Grant to develop the
McQuesten Brook Geomorphic Assessment and
Watershed Restoration Plan in 2013, which ranked
culvert improvements as the second most important
structural recommendation in the watershed. These
obstructions included: (1) an undersized culvert that
carried the brook under a road and served only one
household while constricting the brook and restrict-
ing aquatic organism passage; (2) another undersized
culvert built with enough road fill to meet NHDES'
definition of a dam; and (3) a collapsed stone culvert
that completely blocked the channel and rerouted
McQuesten Brook,

Figure 1. Culverts like this one on Eastman Avenue
blocked fish passage and contributed to low DO.

In mid-May 2016, work began. The Town of Bedford
purchased and demolished the only house accessed
by Wathen Road to the east of the brook, then
removed a 35-foot segment of the road and the
36-inch undersized culvert. This innovative approach
was less costly than upgrading the crossing with an
appropriately sized bridge to provide proper aquatic
organism passage and conveyance of flood flows. The
Town's contractors regraded the floodplain to match
upstream and downstream elevations. To attenuate
floodwaters, they created roughness on the floodplain
with salvaged branches and pieces of large wood held
in place by felled trees. They seeded and planted the
area to minimize erosion. The brook was diverted, and
the culvert was removed in sections. Crews restored
the bed with rounded cobble, and they stabilized the

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channel and banks with bioengineered gravel bars and
crib walls made of logs, stone, and root wads. They
also constructed a log and stone crib with integrated
root wads at the new terminus of Wathen Road. The
design protects a parallel water main and a new deten-
tion and infiltration basin and its overflow outlet.

Upstream and one block north of Wathen Road,
where the brook was constricted, the Town of Bedford
replaced an undersized 36-inch culvert at Eastman
Avenue with a 15-foot open-bottom bridge. This
structure is sized appropriately for aquatic organism
passage and conveyance of flood flows up to one and a
half times bankfuil width (Figure 2).

Immediately upstream of Eastman Avenue, contrac-
tors removed the remnants of a collapsed stream
crossing. This work restored stream channel dimen-
sions, function, and fish passage along a reach of
the brook that previously supported little or no fish
passage. Construction was completed in July 2016.
Concurrently, several obsolete dams were removed
upstream. This effort increased aquatic organism
passage throughout the watershed and connected the
restored culvert sites with upstream reaches, including
McQuesten Pond, which (at that time) was also on the
CWA section 303(d) list due to low DO. McQuesten
Pond was slowly drained, and the area is now a
defined wetland channel.

Results

Addressing these three fish passage impediments
in 2016 re-established a more natural flow regime
in this segment of McQuesten Brook, resulting in
improved DO levels and lower water temperatures,
which created a healthier and more valuable habitat
for eastern brook trout and other aquatic organisms.
After restoration work, the DO threshold of 5.0 mg/L
was met during a wide range of temperatures and
conditions similar to those present while the brook
was impaired (Figure 3). In 2018, NHDES removed this
river assessment unit from the CWA section 303(d) list
for its DO impairment.

Subsequent brook trout population surv eys com-
pleted by New Hampshire Fish and Game Department
biologists revealed that trout size and population
density have increased and are similar to those found
in pristine northern New Hampshire streams.

^tD	y.s. Environmental Protection Agency

0**	Office of Water

\	Washington, DC

• ---''J?	EPA 841-F-22-001LL

pRol^	December 2022

Figure 2. A new bridge crosses Eastman Avenue.

Figure 3. DO levels In McQuesten Brook (2009-2020).

Partners and Funding

The Council's McQuesten Brook restoration plan and
its initiative to partner with the Town of Bedford were
the driving forces behind the daylighting project at
Wathen Road. When the Town agreed to exceed the
scope of their capital improvement plan at this site,
the Council secured multiple grant resources and
engaged a fluvial geomorphologist for specialized
project design and construction oversight.

Funding provided in part by Watershed Assistance
Grant Funds from NHDES, with $50,000 In CWA
section 319 funds from the U.S. Environmental
Protection Agency awarded to the Council, who
served as project manager. Other funds included
$345,000 in NHDES Wetland Bureau Aquatic Resource
Mitigation Funds; $482,504 in matching funds from
the Town of Bedford's Capital Improvement Program,
Including engineering and construction costs; and
another $181,785 in matching funds from the Council,
supported by dues, endowments, gifts, and more.
Specialized contract work was performed by Field
Geology Services and inter-Fluve, Inc.

For additional information contact:

Stephen Landry

New Hampshire Department of Environmental Services
603-271-2969 • stephen.c.landry@des.nh.gov

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