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Ramanessin Brook Restoration Projects Iipprove the Navesink River
Wafprhnrk/ ImnrnvpH Highly erodible soils along a popular recreational area led to the
2006 impairment of Ramanessin Brook for total suspended solids
(TSS) and phosphorus, and to the 2006 impairment of the downstream Navesink River for turbidity.
Best management restoration projects implemented in the Ramanessin Brook watershed reduced
erosion and resulted in the Navesink River being removed from the 2014 Clean Water Act (CWA)
section 303(d) list for turbidity by the New Jersey Department of Environmental Protection (NJDEP),
Problem
Ramanessin Brook flows through Holmde! Township
in Monmouth County, it is a 5-mile-long tributary to
the Navesink River (Hydrologic Unit Code 12 [HUC 12]
020301040303), an important recreation area along
the Jersey Shore (Figure 1). Ramanessin Brook is classi-
fied as FW2-Trout Maintenance by the NJDEP. The soils
of the 6.4-square-mile Ramanessin watershed contain
a relatively high amount of glauconite, a mineral
deposit of marine origin. The glauconitic soils are
highly erodible and are in part the cause of severely
eroded stream banks in the watershed.
in 2005 a CWA section 319(h)-funded study, entitled
"Ramanessin Brook Nonpoint Source Pollution Source
Assessment and Stormwater impact Study," was pre-
pared. The study noted that the erosion of glauconitic
soils and instream erosion are major sources of phos-
phorus and suspended sediment in the watershed.
The study also quantified and mapped subwatersheds
according to their vulnerability to erosion of glauconit-
ic soils and specific pollutants. Specific subwatersheds
having the greatest potential benefit from stormwater
management and stream restoration practices were
identified. Field surveys were conducted to identify
specific projects that would improve water quality.
Project Highlights
Project sites were identified and prioritized, and the
projects were divided into two phases to coincide with
funding and the time needed to obtain permits. Key
projects included:
(1) Village Elementary School courtyard rain gardens.
Rain gardens were installed in 2010 to replace an
underused asphalt courtyard at the school's center.
Roof runoff is sent to four functional rain gardens.
Figure 1. Ramanessin Brook (HUC 02030104070010) is
in the headwaters of the Navesink River watershed on
New Jersey's coast.
Teachers incorporated the rain gardens into the
curriculum and hold outdoor classes monthly to
promote environmental stewardship.
(2) Holmdel High School bioretention basin. Holmdel
High School and an intermediate school are on an
83-acre parcel bordered by Ramanessin Brook to
the east and by a smaller tributary to the west.
A large bioretention basin was constructed to
replace stormwater drainage pipes that had carried
runoff from parking lots and rooftops directly into
Ramanessin Brook at an eroding outfall.
Ramanessin Brook and Navesink River
Legend
~ Counties
Monitoring Location
U MCHD-38
Restoration Projects
~ HUC14 =
02030104070010
Navesink River HUC
12 improved
HUC14
subwatersheds
Navesink River -
Shrewsbury River
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(3) Ramanessin Conservation Area #1 (Chase Tract)
stream restoration. Ramanessin Brook had
severely eroded streambanks and a deeply incised
stream channel within property jointly owned
by NJDEP and Monmounth County. A series of
streambank structures constructed of natural
materials refocused erosive flows toward the
brook's center.
(4) Numerous Holmdel Park projects.
• Hilltop rain gardens, where runoff from a parking
lot had flowed directly into two erosion-producing
stormwater systems. The runoff now discharges
into one of two rain gardens at both ends of the
parking lot.
• Bioretention basin, where runoff from a parking
lot and a steep access road had been conveyed to
a pipe system directly connected to a tributary to
Ramanessin Brook. The project rerouted the runoff
into a new bioretention basin planted with native
vegetation. The majority of the runoff from the
5.7-acre drainage area is now treated and infil-
trated in the bioretention basin.
• Outfall restoration, where a stormwater outfall
from a residential neighborhood was causing gully
erosion in a tributary that flowed into a pond. The
outfall was redesigned to dissipate energy and
alleviate erosion. The eroding ditch was restored
and planted with native vegetation.
• Streambank enhancement, where (with the use of
remaining grant funding) approximately 1,400 native
plants ranging in size from small plugs to 3 feet in
height were planted at the lower end of the Holmdel
Park pond. The additional vegetation provided a
wider buffer around the lower end of the pond to
deter waterfowl and reduce nutrient loading.
Results
The project's goal to improve the water quality
of Ramanessin Brook was achieved by installing
stormwater management and stream restoration
BMPs that were designed to reduce nonpoint source
pollutant loading to the stream from erosion. The
latest data from Station MCHD-38 show no turbidity
exceedances (14 samples), and multiple other stations
within the watershed are also all fully attaining water
quality standards (Figure 2). As a result, the NJDEP
removed the downstream Navesink River HUC 12
(0203010403030) for turbidity from the 2014 CWA
section 303(d) list.
Partners and Funding
NJDEP awarded Monmouth County a total of
$1,383,900 in CWA section 319(h) funding for
project design and implementation. The grant was
administered by the Monmouth County Division of
Engineering and the Monmouth County Park System.
Additional partners within Monmouth County
included the Finance, Purchasing, Planning and Shade
Tree Commission offices. Other project partners
included the Holmdel Township Board of Education,
the Holmdel Township Environmental Commission,
and Rutgers Cooperative Extension Water Resources
Program, numerous students and volunteers. The
New Jersey AmeriCorps Watershed Ambassadors
also participated in project implementation. Omni
Environmental provided design, construction docu-
ments and construction oversight.
In 2010 the New Jersey American Water Resources
Association (NJAWRA) recognized the Village
Elementary School Courtyard Rain Gardens as an
Exceptional Stormwater Management Project. In
addition, remaining projects received the NJAWRA
2014 Excellence in Water Resources Protection and
Planning Award.
Navesink River Turbidity
Restored HUC14: 02030104070110
200
100
S' 80
5
;o
| 60
40
20
Max. of 30 NTU at any time
Max. 30-day avg. of 10 NTU
Trend Line
I 1 1 1 1
rCv M'
S3
$ & ^
,s<" ..S- ..S-
Figure 2. Turbidity levels have fallen steadily.
^edsj^ U.S. Environmental Protection Agency
0** Office of Water
^ Washington, DC
WJ
EPA 841-F-17-00111
pRot^° December 2017
For additional information contact:
Jay Springer
New Jersey Department of Environmental Protection
609-633-1441 • jay.springer@dep.nj.gov
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