[Ord. No. 08-1852 §1, 2-19-2008]
This Chapter shall be known as the "City of Manchester's Post-Construction
Stormwater Runoff Plan".
[Ord. No. 08-1852 §1, 2-19-2008; Ord. No. 09-1967 §1, 12-21-2009]
The following words, as used in this Chapter, shall have the
following meanings:
A process to remove soluble pollutants from stormwater runoff
passing through clay and organic particles which hold negative charges.
A process in which organic contaminants can be broken down
by the action of aquatic microorganisms in stormwater.
A process in which concentrations of nutrients are used by
aquatic plants, algae, microorganisms and phytoplankton for growth.
Best Management Practice are methods to control point and
non-point pollutants at levels compatible with environmental quality
goals.
This can occur in ponds and wetlands which provide the conditions
necessary for the conversion of certain organic compounds into simpler
compounds.
The removal of particulates from water by passing the water
through a porous media.
The separation of particulates with a specific gravity less
than that of water.
Elevation difference.
Facilities which are subject to stormwater effluent limitations
and are known producers of contaminated runoff.
The characteristic pattern of precipitation, runoff, infiltration
and evaporation affecting a water body.
Land surfaces with a low capacity for soil infiltration,
such as pavements, roofs, building surfaces or other human structures.
The process by which stormwater runoff permeates downward
through the earth.
Missouri Department of Natural Resources.
Municipal Separate Storm Sewer Systems.
Pollution caused by rainfall or snowmelt moving over and
through the ground picking up and carrying away natural and human-made
pollutants.
The removal of suspended particles from the water column
by gravitational settling.
A natural depression in a land surface indicating a subterranean
passage, generally occurring in limestone regions and formed by solution
or by collapse of a cavern roof.
Stormwater Pollution Prevention Plan — A construction
phase plan for using soil and erosion control best management practices
(BMPs).
An area that is inundated or saturated by surface water or
ground water with vegetation adapted for life under those soil conditions
and is considered a swamp, marsh or other similar area that supports
natural vegetation that is distinct from the adjacent upland areas.
[Ord. No. 08-1852 §1, 2-19-2008]
A.
Land
development projects and associated increases in impervious cover
alter the hydrologic response of local watersheds and increase stormwater
runoff rates and volumes, flooding, stream channel erosion and sediment
transport and deposition. Stormwater runoff, soil erosion and non-point
source pollution can be controlled and minimized through the regulation
of stormwater runoff from development and redevelopment sites.
B.
The City
of Manchester, therefore, establishes this set of water quality and
quantity regulations applicable to all surface waters to provide reasonable
guidance for the control of stormwater runoff for the purpose of protecting
local water resources from degradation. It is determined that the
regulation of stormwater runoff discharges from land development and
redevelopment projects, plus other construction activities, in order
to control and minimize increases in stormwater runoff rates and volumes,
soil erosion, stream channel erosion and non-point source pollution
associated with stormwater runoff is in the public interest and will
prevent threats to public health, safety and welfare.
[Ord. No. 08-1852 §1, 2-19-2008]
A.
The purpose
of this Chapter is to establish minimum stormwater management requirements
and controls to protect and safeguard the general health, safety and
welfare of the public residing in watersheds within the City of Manchester.
This Chapter seeks to meet that purpose through the following objectives:
1.
Minimize
increases in stormwater runoff from any development in order to reduce
flooding, siltation, increases in stream temperature and stream bank
erosion and maintain the integrity of stream channels;
2.
Minimize
increases in non-point source pollution caused by stormwater runoff
from developments which would otherwise degrade local water quality;
3.
Make
efforts to minimize the total annual volume of surface water runoff
which flows from a specific site during and following development
to not exceed the pre-development hydrologic regime to the extent
determined practicable by the City;
4.
Reduce
stormwater runoff rates and volumes, soil erosion and non-point source
pollution, wherever possible, through stormwater management controls
and to ensure that these management controls are properly maintained
and pose no threat to public safety;
5.
Improve
development design in the following way:
a.
By
providing a planned mixture of land uses while maintaining adequate
open space, common facilities, and buffers between uses;
b.
By
permitting land use designs that incorporate natural terrain features,
to preserve trees and natural open spaces and encourage the philosophy
of design with nature;
c.
By
providing a mixture of housing types while maintaining density standards
to protect residents from overdevelopment;
d.
By
allowing non-residential uses within the development, thereby discouraging
strip commercial development;
e.
By
encouraging pedestrian and non-motorized vehicle paths and ways utilizing
natural terrain features rather than traditional design;
f.
By
permitting the accommodation of alternative energy systems which might
not otherwise be permitted;
g.
Where
feasible, secure a conservation easement from new developments to
protect the natural resources on existing land parcels. Such conservation
easements would not prohibit the installation of sanitary and storm
sewers, ponds, wetlands or other best management practices (BMPs)
that may be appropriate in these areas.
