Stormwater Management Standards Manual - Toledo Metropolitan ...

CHAPTER 7 - Riparian Setbacks
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7.0 Chapter Summary
• This chapter is intended to:
• introduce the concept of riparian setbacks and describe their purpose as a runoff control method,
flood control method and effect on water quality and the riparian environment,
• describe how, when, where and to what extent riparian setbacks should be established,
• list the uses that should be permitted and prohibited in the riparian setback,
• recommend procedures for granting variances within the riparian setback and inspecting the
same.
7.1 Introduction
Flooding and stream bank erosion are threats to public health and safety, and to public and private
property. Vegetated riparian areas lessen the damage from flooding by slowing runoff, enabling water to
soak into the ground, and by absorbing excess flow during flood events.
The NPDES permit authorizing discharges from MS4s requires that jurisdictions governed by the permit
“protect sensitive areas such as wetlands and riparian areas, maintain or increase open space, provide
buffers along sensitive water bodies, minimize impervious surfaces, and minimize disturbance of soils
and vegetation. Adoption of local regulation that minimize disturbance and land conversion from
pervious to impervious surfaces in riparian areas limit the adverse affects of runoff. This section
describes control measures for Riparian Setbacks and best management practices for establishing the
setbacks.
Preliminary plans, building or zoning approvals should be conditioned on compliance with the riparian
setback regulations where applicable. Individual jurisdictions may have established specific ordinances
or subdivision regulations which vary from the Riparian Setbacks recommended in this Stormwater
Standards Manual. It is also recommended that jurisdictions that adopt riparian setbacks include a
variance procedure.
7.2 Purpose
The value of establishing permanent vegetation on stream banks and within some distance from stream
banks is to:
• Reduce flood impacts by absorbing peak water flows, slow the velocity of floodwaters and
regulate base flow of waters.
• Stabilize the banks of streams to reduce bank erosion and the downstream transport of
sediments eroded from stream banks.
• Reduce pollutants in streams during periods of high flows by filtering, settling and
transforming pollutants already present in streams and in removing pollutants before they
reach the stream.
• Provide areas for natural meandering and lateral movement of stream channels.
• Reduce the presence of aquatic nuisance species to maintain diverse and connected
riparian vegetation.
Third Edition Stormwater Standards Manual September 2008 Page 116