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<regulation prefix="Regulation" num=".08" citation="COMAR 26.17.02.08" title_num="26" subtitle_num="17" chapter_num="02" heading="Stormwater Management Measures.">
  <paragraph num="A.">
    <text>The ESD planning techniques and practices and structural stormwater management measures established in this regulation and the Design Manual shall be contained in all county and municipal ordinances. Each ordinance shall require that a developer demonstrate that ESD has been implemented to the MEP and, only where absolutely necessary, is a structural BMP used in developing a stormwater management plan.</text>
  </paragraph>
  <paragraph num="B.">
    <text>ESD Planning Techniques and Practices.</text>
    <paragraph num="(1)">
      <text>The following planning techniques shall be applied according to the Design Manual to satisfy the minimum control requirements established in Regulation .06 of this chapter:</text>
      <paragraph num="(a)">
        <text>Preserving and protecting natural resources;</text>
      </paragraph>
      <paragraph num="(b)">
        <text>Conserving natural drainage patterns;</text>
      </paragraph>
      <paragraph num="(c)">
        <text>Minimizing impervious area;</text>
      </paragraph>
      <paragraph num="(d)">
        <text>Reducing runoff volume;</text>
      </paragraph>
      <paragraph num="(e)">
        <text>Using ESD practices to maintain 100 percent of the average annual predevelopment groundwater recharge volume for the site;</text>
      </paragraph>
      <paragraph num="(f)">
        <text>Using green roofs, permeable pavement, reinforced turf, and other alternative surfaces;</text>
      </paragraph>
      <paragraph num="(g)">
        <text>Limiting soil disturbance, mass grading, and compaction;</text>
      </paragraph>
      <paragraph num="(h)">
        <text>Clustering development; and</text>
      </paragraph>
      <paragraph num="(i)">
        <text>Any practices approved by the Administration.</text>
      </paragraph>
    </paragraph>
    <paragraph num="(2)">
      <text>The following ESD treatment practices shall be designed according to the Design Manual to satisfy the minimum control requirements established in Regulation .06 of this chapter:</text>
      <paragraph num="(a)">
        <text>Disconnection of rooftop runoff;</text>
      </paragraph>
      <paragraph num="(b)">
        <text>Disconnection of nonrooftop runoff;</text>
      </paragraph>
      <paragraph num="(c)">
        <text>Sheetflow to conservation areas;</text>
      </paragraph>
      <paragraph num="(d)">
        <text>Rainwater harvesting;</text>
      </paragraph>
      <paragraph num="(e)">
        <text>Submerged gravel wetlands;</text>
      </paragraph>
      <paragraph num="(f)">
        <text>Landscape infiltration;</text>
      </paragraph>
      <paragraph num="(g)">
        <text>Infiltration berms;</text>
      </paragraph>
      <paragraph num="(h)">
        <text>Dry wells;</text>
      </paragraph>
      <paragraph num="(i)">
        <text>Micro-bioretention;</text>
      </paragraph>
      <paragraph num="(j)">
        <text>Rain gardens;</text>
      </paragraph>
      <paragraph num="(k)">
        <text>Swales;</text>
      </paragraph>
      <paragraph num="(l)">
        <text>Enhanced filters; and</text>
      </paragraph>
      <paragraph num="(m)">
        <text>Any practices approved by the Administration.</text>
      </paragraph>
    </paragraph>
    <paragraph num="(3)">
      <text>The use of the ESD planning techniques and treatment practices specified in this section may not conflict with existing State law or local ordinances, regulations, or policies. Counties and municipalities shall modify planning and zoning ordinances and public works codes to eliminate any impediments to implementing ESD to the MEP according to the Design Manual.</text>
    </paragraph>
  </paragraph>
  <paragraph num="C.">
    <text>Structural Stormwater Management Measures.</text>
    <paragraph num="(1)">
      <text>The following structural stormwater management practices shall be designed according to the Design Manual to satisfy the applicable minimum control requirements established in Regulation .06 of this chapter:</text>
      <paragraph num="(a)">
        <text>Stormwater management ponds;</text>
      </paragraph>
      <paragraph num="(b)">
        <text>Stormwater management wetlands;</text>
      </paragraph>
      <paragraph num="(c)">
        <text>Stormwater management infiltration;</text>
      </paragraph>
      <paragraph num="(d)">
        <text>Stormwater management filtering systems; and</text>
      </paragraph>
      <paragraph num="(e)">
        <text>Stormwater management open channel systems.</text>
      </paragraph>
    </paragraph>
    <paragraph num="(2)">
      <text>The performance criteria specified in the Design Manual with regard to general feasibility, conveyance, pretreatment, treatment and geometry, environment and landscaping, and maintenance shall be considered when selecting structural stormwater management practices.</text>
    </paragraph>
    <paragraph num="(3)">
      <text>Structural stormwater management practices shall be selected to accommodate the unique hydrologic or geologic regions of the State.</text>
    </paragraph>
  </paragraph>
  <paragraph num="D.">
    <text>Standard Plans.</text>
    <paragraph num="(1)">
      <text>Compliance with any of the following Standard Plans is considered to satisfy the minimum control requirements established in Regulation .06A(2) of this chapter.</text>
    </paragraph>
    <paragraph num="(2)">
      <text>Standard Plans. The following documents are incorporated by reference:</text>
      <paragraph num="(a)">
        <text>Standard Stormwater Management Plan for Agricultural Structures (SSDS — SP01);</text>
      </paragraph>
      <paragraph num="(b)">
        <text>Standard Stormwater Management Plan for Poultry House Development on Maryland’s Eastern Shore (SSDS — SP02); and</text>
      </paragraph>
      <paragraph num="(c)">
        <text>Standard Stormwater Management Plan for Single Lot Residential Construction (SSDS — SP03).</text>
      </paragraph>
    </paragraph>
    <paragraph num="(3)">
      <text>Compliance with an approved Soil Conservation and Water Quality Plan (SCWQP) is considered to satisfy the minimum control requirements established in Regulation .06A(2) of this chapter if the development:</text>
      <paragraph num="(a)">
        <text>Is an agricultural structure, or associated access roads and parking areas;</text>
      </paragraph>
      <paragraph num="(b)">
        <text>Complies with USDA Natural Resources Conservation Service Maryland Conservation Practice Standard Stormwater Runoff Control Code 570 (March 2013);</text>
      </paragraph>
      <paragraph num="(c)">
        <text>Is not located within the Chesapeake and Atlantic Coastal Bays Critical Area; and</text>
      </paragraph>
      <paragraph num="(d)">
        <text>Is not subject to the requirements of:</text>
        <paragraph num="(i)">
          <text>COMAR 26.08.04.09A;</text>
        </paragraph>
        <paragraph num="(ii)">
          <text>COMAR 26.08.04.09N; or</text>
        </paragraph>
        <paragraph num="(iii)">
          <text>COMAR 26.17.04.05.</text>
        </paragraph>
      </paragraph>
    </paragraph>
    <paragraph num="(4)">
      <text>An approving agency may require more than the minimum control measures. An approving agency may require that an engineered stormwater management plan be submitted if:</text>
      <paragraph num="(a)">
        <text>Otherwise required by statute or regulation;</text>
      </paragraph>
      <paragraph num="(b)">
        <text>The plan fails to meet ESD to the MEP;</text>
      </paragraph>
      <paragraph num="(c)">
        <text>Hydrologic or topographic conditions warrant; or</text>
      </paragraph>
      <paragraph num="(d)">
        <text>Flooding, stream channel erosion, or water quality problems exist downstream from a proposed project.</text>
      </paragraph>
    </paragraph>
  </paragraph>
  <paragraph num="E.">
    <text>County and municipal ordinances shall specify that the ESD planning techniques and treatment practices and structural stormwater management measures used to satisfy the minimum control requirements in Regulation .06 of this chapter are documented and remain unaltered by subsequent property owners. Approval from the appropriate approving agency should be obtained before any stormwater management practice is altered.</text>
  </paragraph>
  <paragraph num="F.">
    <text>Alternative ESD planning techniques and treatment practices and structural stormwater management measures may be used for new development runoff control if they meet the performance criteria established in the Design Manual and are approved by the Administration. Practices used for redevelopment projects shall be approved by the appropriate approving agency.</text>
  </paragraph>
  <paragraph num="G.">
    <text>For purposes of modifying the minimum control requirements or design criteria, the owner/developer shall submit to the approving agency an analysis of the impacts of stormwater flows downstream in the watershed. The analysis shall include hydrologic and hydraulic calculations necessary to determine the impact of hydrograph timing modifications of the proposed development upon a dam, highway, structure, or natural point of restricted streamflow, established with the concurrence of the approving agency, downstream of the first downstream tributary whose drainage area equals or exceeds the contributing area to the project or stormwater management facility.</text>
  </paragraph>
</regulation>