Page 160 - Michigan City, IN US Highway 421 Corridor Plan

5.3 Design Guidelines

Low-Impact Development (Green Infrastructure
and Stormwater Management
To maintain and/or restore the pre-development hydrologic
regime of the site without solely using traditional storm drainage
conveyance systems (e.g., gray infrastructure – pipes and
culverts) to satisfy drainage and flood mitigation requirements.
Integrate small-scale measures scattered throughout the
development site, including such things as constructed
green spaces, native landscaping, and a variety of innovative
bioretention (e.g., bioswales) and infiltration techniques to
capture and manage stormwater on-site and reduce peak
runoff by allowing rainwater to soak into the ground, evaporate
into the air, or collect in storage receptacles for irrigation
and other beneficial uses. In areas with slow drainage or
infiltration, capture the first flush before excess stormwater
and divert into traditional storm conveyance systems.
— Where possible, throughout the site’s ground surfaces, use
surface materials with a low runoff coefficient (the rate that
rainfall contributes to runoff).
— Where possible, install pervious pavement on sidewalks,
pedestrian walkways, overflow parking areas, and other
paved surfaces to reduce storm water runoff, and allow
rainfall to recharge groundwater. Pervious paving that
includes the use of liners and under drains can be
successfully implemented in areas where infiltration
restrictions exist.
— Where paved surfaces are not permeable, direct storm
water flow across streets and sidewalks to bioswales or
to central collection points such as cisterns or permeable
areas with well-drained sands, gravels and soils with
moderately coarse textures, to collect, absorb and filter
rainwater.
— Where possible, incorporate on-site micro-detention basins Dumpster Enclosure Rain Gardens and Green Roofs
(e.g., rain gardens), storm water planters, vegetated swales Service, utility, and mechanical equipment that is visible from the street All new development shall be designed with a commitment to sustainability
(e.g., bioswales) adjacent to plaza, sidewalk, and off-street shall be screened from view with landscaping or enclosures. at both the site and buiding level.
surface parking lot areas.
— Building roofs should incorporate one or more devices for
rainfall collection, storage and reuse. They may include, but
not be limited to:
» green roofs;
» roof decks and terraces that provide equipment to
harvest, filter and store rainfall;
» rain barrels, water cisterns installed above or below
ground (if technically feasible due to remediation
efforts), or other systems that can filter and store water
for use on-site, rather than direct water to a combined
sewer system.
5-41

Adopted: August 16, 2016 Implementation 5.0