OPPORTUNITIES AND CHALLENGES OF IMPLEMENTING TMDLS IN STATES WITH NO INSTREAM FLOW PROGRAMS

Abstract

The connection between water quality and water quantity is intrinsic and an inherent part of theTotal Maximum Daily Load (TMDL) program. Via the Clean Water Act (CWA), Congressdirected the Environmental Protection Agency to restore and maintain the chemical, physical,and biological integrity of our nations waters. In 1994, the Supreme Court reiterated that theintent of the CWA is to ensure physical and biological integrity as well as chemical. Instreamflows necessary to protect and sustain designated uses are one component of physical integrity. The CWA also recognizes that the authority of each state to allocate water quantity shall not beimpaired by the CWA. The state agency charged with administering the CWA and the stateagency charged with managing water quantity are often separated by physical location,organizational structure, customer base, and constituencies. Several states in the arid westrecognize it is often impractical if not impossible to improve water quality unless water quantityissues are concurrently addressed. Water quality professionals are attempting to address thisissue through TMDL Implementation Plans. Such plans may include: 1) management of existingand new surface water rights and ground water rights where ground water is hydrologicallylinked to the impaired surface water, through proper metering and reporting; 2) development andrealization of effective on-farm conservation measures and best management practices; and 3)development and evaluation of conservation plans for all municipal users in the watershed toensure waters are conserved and used efficiently. (The intent of this paper is to discuss the relationship between water quality and quantity in NewMexico related to the creation and implementation of TMDLs. This paper does not represent anofficial New Mexico Environment Department perspective on the issue of water quality vs.quantity.)