Agenda - Planning Commission - 02/02/2017

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Subpart 6. Permit conditions. To assure the protection of those resources intended to be protected through the establishment of the MRCCA, land alteration permits are designed to meet minimum performance standards. These standards are best management practices, typical of contemporary erosion control practices, and include: • temporary and permanent erosion and sediment control; • maximizing natural site topography, soil and vegetation to minimize runoff and reduce erosion and sedimentation; • phasing of construction; and • placement of controls prior to land disturbance, and other BMPs identified in Best Practices for Meeting DNR General Public Waters Work Permit GP 2004-001. Subpart 7. Storm water management. Because of the adverse impact of runoff on bluff and slope stability, this subpart requires that, except as described below, storm water throughout the MRCCA must be directed away from bluff impact zones and other unstable areas. • Storm water management facilities in the bluff impact zone. A contributing factor to slope failure and slumping and the associated economic, ecological and human costs is the poor construction and placement of storm water management facilities, such as pipes, outfalls, and treatment facilities. For this reason, the placement of storm water management facilities in the bluff impact zone is prohibited except in rare circumstances as permitted by local government, including where there are no alternatives, the facility is designed to reduce runoff in the bluff impact zone to the greatest extent practicable, the facility does not affect slope stability, and mitigation measures are incorporated into the permit to eliminate or minimize the risk of slope failure. • Impervious surfaces in the water quality impact zone. Because of the potential adverse water quality impacts attributed to impervious surfaces, proposed Minn. R. 6106.0120, subp. 3 prohibits the placement of impervious coverage in the shore impact zone or bluff impact zone except as expressly provided in proposed Minn. R. 6106.0180, the exceptions. For these exceptions that create new impervious coverage, or for projects that fully reconstruct more than 10,000 square feet of existing impervious coverage, this subpart requires a local government to permit these projects according to the treatment standards in the local government's MPCA- approved Municipal Separate Storm Sewer System Permit (MS4) NPDES permit. If the local government does not have a MS4 NPDES permit, then the treatment standards in the applicable NPDES Construction Storm Water General permit apply. Alternatively, local governments may apply other MPCA-approved treatment standards such as those in the MPCA's voluntary Minimal Impacts Design Standards (MIDS)20 program. 20 http://www.pca.state.mn.us/index.php/water/water-types-and-programs/stormwater/stormwater-minimal- impact-design-standards-mids.html 61