In 2004, the Bureau of Land Management in cooperation with the U.S. Army Corps of Engineers completed the Supplemental Programmatic Environmental Impact Statement for the Clark County Regional Flood Control District Master Plan Update or SEIS. The SEIS was an update to the original Environmental Impact Statement (EIS) that was completed in 1991.

The purpose of the 1991 EIS and the subsequent SEIS was to assess the environmental impacts associated with implementation of the District's Master Plan Updates for the Las Vegas Valley and Boulder City.  Because many of these facilities are planned to be constructed on land owned and managed by the federal government, the EIS and SEIS were required to evaluate the impacts associated with BLM issuance of rights-of-way for the development of flood control facilities on federal land.

The SEIS outlines project-specific procedures by which each new District facility will be reviewed to ensure full compliance with environmental regulatory requirements and to minimize potential environmental  impacts during construction, operation an maintenance of flood control facilities.  This process - referred to as the "Section 8" or "Chapter 8" process - is outlined in detail in Chapter 8 of the SEIS.  This project specific analysis is only required for projects outlined in the Las Vegas Valley Master Plan Update, the Boulder City Master Plan Update or for projects requiring a 404 Clean Water Act permit using Regional General Permit 7.