No person shall submit a special permit, subdivision, or resubdivision
application without including a stormwater management plan that will
control or manage runoff from the land, except as provided within
this article. Furthermore, upon application for a certificate of zoning
compliance the Commission may require that a Stormwater Management
Plan be prepared, all or in part, as provided within this article
when it has been determined that the development of the single-family
dwelling may have an adverse impact on stormwater quality.
No stormwater management plan may be approved without a finding
that the plan is consistent with the CT Stormwater Quality Manual
and the following criteria:
A. Design and planning for site development shall provide for minimal
disturbance of predevelopment natural hydrologic conditions, and shall
reproduce such conditions after completion of the proposed activity,
to the maximum extent feasible as determined by the Town Engineer
in accordance with the CT Stormwater Quality Manual.
B. Pollutants shall be controlled at their source to the maximum extent
feasible in order to contain and minimize contamination. Methods include
but are not limited to sweeping of pavements, especially in the early
spring, the use of sediment basins prior to infiltration and encouragement
of sheet flow to filter strips. Snow removal should be placed on a
site that will not cause pollution as defined in this section.
C. All stormwater management systems shall be designed and maintained
to manage site runoff in order to eliminate surface and groundwater
pollution, prevent flooding and, where required, control peak discharges
and provide pollution treatment.
D. All stormwater management systems shall be designed to collect, retain
and treat the first inch of rain on site, so as to trap floating material,
oil and litter. On-site storage methods include but are not limited
to landscaped depressions, grass swales, infiltration trenches and
retention or detention basins.
E. Stormwater runoff rates and volumes shall be controlled by slowing
runoff velocities and infiltration. BMP methods for controlling runoff
and infiltration shall be in accordance with the CT Stormwater Quality
Manual. Stormwater management plans must demonstrate as close to a
zero increase in runoff for the two-, ten-, twenty-five-, fifty-,
and one-hundred-year design storms as compared to predevelopment conditions
as is practicably possible based on site soil conditions.
F. All stormwater treatment systems shall be employed where necessary
to ensure that the average annual loadings of total suspended solids
following the completion of the proposed activity at the site are
no greater than such loadings prior to the proposed activity. Alternatively,
stormwater treatment systems shall remove 80% of total suspended solids
from the site on an average annual basis.