07/26/2000 Env Bd Packet - Laserfiche WebLink

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WHAT YOU CAN Do Without a doubt, the control of impervious surfaces is most effectively addressed at the city and township level. By the time a development plat or street construction plan reaches the District, it is often too late to economically incorporate large design revisions. - Municipalities and local governmental units can help by: 1. UPDATING ORDINANCES Ordinances can be redefined to reduce pervious surface losses during development and to preserve infiltration. Examples include: • Zoning, which set maximum impervious limits. • Landscaping ordinances, which create areas where stormwater can infiltrate. • Stormwater management, requirements for development to control runoff volumes in addition to runoff rates. • Promoting cluster development reduces the amount of road surfaces needed for the community. Added benefits are: O Reduced capital cost of development (10 to 33 %). o Reduced site imperviousness (10 to 50%). o Reduced size and cost of stormwater quantity and quality controls. 2. REVISING STANDARDS Standards can be revised to minimize impervious surfaces. Examples include: • Parking lot standards to reduce paved areas that contribute to runoff. Some standards to consider are: Use of overflow lots with more permeable surfaces. Shared lots for businesses with different peak operation times. Smaller parking stall dimensions. Reduced number of parking stalls required for each land use. Many commercial parking lots are over designed with around 20% excess capacity during normal peak usage. • Street width standards can allow for variable widths based on traffic counts. " Narrower streets mean less impervious area and less construction and maintenance costs. Mature tree loss is reduced. Reducing road width • by 6 ft can reduce road contributions to impervious surfaces by 15 %.