Construction General Permit SWPPP Development Resources
The resources below can be used to assist in the development of a Stormwater Pollution Prevention Plan (SWPPP).
Mapping
| Description | Link |
|---|---|
| Mapping Website used to determine Lat and Long if no other resources are available. | iTouchMap Latitude and Longitude |
| Map of DEC Contaminated Sites. | Contaminated Sites |
| A source for topographical information for the development of general location maps as well as drafting the project site specific conditions. The Anadromous Waters Catalog interactive map is useful for gathering this site information. | Alaska Department of Fish and Game Interactive Maps |
Precipitation and Runoff
| Description | Link |
|---|---|
| General runoff coefficient values based on hydrologic soil group and ground slope which can be used in the rational equation to determine peak stormwater runoff values. | Table 3-6 |
| Precipitation data for Alaska weather-recording stations. This site is also used to determine the “Spring Thaw” and “Fall Freeze-up” dates for determination of the winter shutdown period. This information can be found by scrolling down to “Temperature” under the “Period of Record” and going to either “Spring Freeze Probabilities” or “Fall Freeze Probabilities”. Areas identified as “Arid (<10in)” and “Semi-Arid (10-20 in)” can also be identified on this website by reviewing the annual average precipitation. | Western Regional Climate Center Internet website |
| Determine the rainfall values for specified storm events. | National Weather Service Technical Paper No. 47 “Probable Maximum Precipitation and Rainfall-Frequency Data for Alaska” |
| The calculation of precipitation intensity values for different storm events throughout Alaska. | NOAA Hydrometer logical Design Studies Center- Precipitation Frequency Data Server (PFDS) |
| A web based innovative tool which can be downloaded to calculate stormwater runoff from an individual parcel. | EPA National Stormwater Calculator |
| Detailed guidance on calculating Peak Stormwater Runoff Rates in Rational Method Calculations. | Rational Method for Calculation of Peak Stormwater Runoff Rates |
| Example of General Training Material to calculate stormwater discharges with the Rational Method. | Rational Method Hydrologic Calculations |
Soils and Growing Seasons
| Description | Link |
|---|---|
| To obtain the STATSGO Soils Data for uploading to GIS or use the more general Web Soil Survey for general soil information of your project area. | NRCS Soil Survey Information website |
| Alaska growing season periods are defined by Ecoregion on Page 51 in the Corps of Engineers Wetland Delineation Manual. | US Army Corps of Engineers Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Alaska Region (Version 2.0) |
| NRCS resource that can be used to calculate Sediment discharge quantities from a construction site dependent on soil cover, soil type, etc. | NRCS- Revised Universal Soil Loss Equation, Version 2 (RUSLE 2) |
Protection Areas
| Description | Link |
|---|---|
| Impaired Waters and TMDL Listings. | Integrated Report |
| The Alaska Office of History and Archaeology may need to be consulted if the project area is expected to be in an archaeologically sensitive area. | Alaska Office of History and Archaeology |
Best Management Practices
| Description | Link |
|---|---|
| The Alaska Stormwater Guide can be used to assist with the development of site plans and BMP selection. | Alaska Stormwater Guide |
| Appendix B of the Alaska Stormwater Guide includes BMP Specifications. | Appendix B of the Alaska Stormwater Guide |
| Resource for various erosion and sediment control BMPs with some detailed information for the design of sediment basins. | California Department of Transportation (Caltrans) Construction Site BMPs Manual |
| Detailed guidance on region-appropriate plant species and revegetation methods. | A Revegetation Manual for Alaska (2008) |
| Information about native seed suppliers, seed mixtures, and other valuable revegetation information. | Alaska Plant Materials website |
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