Projects > Stormwater Assessment and Retrofit Inventory of Route 1
The
storm water outfall
study was completed in the Fall of 2004 by the Maine State Planning
Office and the report has been presented to the Town of Kittery (view
the slides from the presentation).
The study focused on the "urbanized" section of the Spruce
Creek watershed occupied by the Route 1 commercial corridor and was designed
to identify and track the movement of storm run off from the many impervious
road and parking lot surfaces, specifically those portions of the malls
and Route 1 where the Maine Department of Transportation has ownership
of the roadway and outfalls.
The report has been presented to the Kittery Town Manager, Jon Carter, the Town Planner, and the Commissioner of Public Works. The Town can now decide if they'd like to pursue applying for MDOT Surface Water Quality Protection Program funds (part of the Federal Transportation Enhancement Act for the 21st Century or "TEA-21") to remedy some of the more troublesome stormwater issues. We have also given a copy to our partners at the Wells Reserve.
The Route I storm water study presents a very interesting set of findings and recommendations and a clear picture of where problems exist in that part of our watershed. This large, detailed and technical study adds another "layer" to our assessment activities. Its data will help us determine exactly how much of a problem non-point source pollution is to Spruce Creek.
Please view the study and if you have any questions or would like to see some of the maps, feel free to contact us.
Executive
Summary of the Project
A
stormwater assessment and retrofit inventory of Route 1 within the commercial
area in Kittery, Maine was undertaken by Hillier & Associates, Inc.
in the fall and winter of 2004. The analysis was assigned by the Maine
State Planning Office to determine the extent and location of various
publicly-owned stormwater inputs to the Spruce Creek watershed and to
identify possible stormwater best management practice retrofit locations
within the area. The public roadway and its stormwater infrastructure
were specifically analyzed in order to compete for possible funding through
the MaineDOT's Surface Water Quality Protection Program.
The
stormwater assessment revealed nine discrete subcatchment areas that convey
stormwater from the public right-of-way. These stormwater drainage systems
often convey a combination of public and private stormwater runoff. The
subcatchment contributing areas ranged from 0.17 acres to 11.9 acres in
size and had corresponding peak flow rates for the 1-yr storm event of
0.46 cfs to 23.23 cfs, respectively. Subcatchments along the study corridor
ranged from a low of 0% privately-owned contributing area (Subcatchment
3, 5, and 6) to a high of 96% privately-owned contributing area (Subcatchment
4). Of the nine subcatchment areas only three contributed stormwater from
Route 1 exclusively. Stormwater pollutant loads for each subcatchment
were estimated for the 1-inch, 24-hour storm event using the urban runoff
model, P8. TSS pollutant loads for this storm event ranged from 0.35 lbs
to 175 lbs, with loading values correlated to contributing area size.
The P8 model load output incorporates possible treatment at outlet buffers
and swales. Water quality tests were performed on grab-samples for one
storm event in early December. The samples indicate high levels of bacteria
loading and high levels of hydrocarbon loading from selected subcatchments.
The stormwater retrofit inventory revealed 21 locations for possible stormwater best managment practice retrofit options within or near the analyzed subcatchments. The significant areas of private land stormwater runoff to the public storm drain system will limit the opportunities for effective stormwater treatment within the public right of way. Therefore, we recommend efforts to reduce or eliminate private sources of water to the public stormwater drainage network when opportunities exist.
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