Stormwater Phase II

Storm Water Phase II

The Storm Water Phase II regulations expanded the storm water program.

SDDOT Pocket Guide, Erosion & Sediment Control

SDDENR - Storm Water Phase II - Storm Water Permit for Construction Activities

Any construction activity that disturbs one or more acres must submit a Notice of Intent (NOI) for coverage under the Phase II storm water general permit for construction activities 15 days prior to construction. Sites smaller than 1 acre that are related to a larger scale plan or project may also need a permit if the total plan meets the minimum 1 acre requirement. Pertinent construction activities requiring coverage under this permit include:

  • Clearing, grading, or excavation;
  • Road building;
  • Construction of residential, commercial, and industrial buildings;
  • Installing pipelines, cable lines, and phone lines; and
  • Demolition activities.

A Notice of Termination (NOT) must be submitted after the permitted site is stabilized. A site is considered stabilized if 70% of the site is covered by established vegetation.

A Storm Water Pollution Prevention Plan (SWPPP) must be completed prior to start of construction.

Storm Water Phase II - Storm Water Permit for Industrial Activities - This general permit authorizes all new and existing storm water discharges associated with industrial activity for nine categories. These categories are explained within the general permit on the SDDENR website.

Storm Water Phase II - Storm Water Permit for Municipal Storm Sewer Systems (MS4s) (SDDENR)

The Storm Water Phase II Rule extends coverage of the NPDES storm water management program to certain "small" MS4s. Phase II takes a slightly different approach than Phase I as to how the storm water management program is developed and implemented. A small MS4 is any MS4 not already covered by the Phase I program as a medium or large MS4. The Phase II program is designed to accommodate a general permit approach using a Notice of Intent (NOI) as the permit application. The Phase II Rule automatically covers all MS4s officially designated as urbanized areas that reflect populations between 10,000 and 100,000. The SDDOT is included in the MS4 designation as it has shared storm water systems responsibilities within the municipalities. The designated MS4s in South Dakota include:

      Storm Water Phase II MS4 Entities
  • Aberdeen
  • Huron
  • North Sioux City
  • Pierre
  • Sturgis *
  • Watertown
  • Pennington County *
  • Brookings
  • Mitchell
  • Rapid City
  • Spearfish
  • Vermillion
  • Yankton
  • SDDOT - * Voluntary MS4 Participation

  • All covered entities, including DOT, were required to submit a Notice of Intent (NOI) and a Storm Water Management Plan (SWMP) by March 10, 2003 to comply with the state-issued general permit. The SDDOT Storm Water Management Program (SWMP) applies to its many miles of right-of-way and roads, rest areas, weigh stations and other properties throughout defined urbanized areas within South Dakota.

    A SWMP consists of the following six minimum control measures as identified by the EPA:

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