Indiana, uses a watershed management approach to controlling NPS pollution. The plan began by identifying roughly 1,500 water body-pollutant combinations that would require a TMDL under the CWA section 303(d). The plan takes a three tiered approach to implement management measures for NPS pollution. The first tier considers "self-determined implementation of best management practices." This essentially considers voluntary programs, grants, and education. California has a number of educational programs designed to help alert local policymakers to the problems associated with NPS pollution, including the California Water and Land Use Partnership and the Model Urban Runoff Program. Incentive programs under this tier include measure like financial assistance for local watershed stewardship projects through grants from the CWA section 319 and environmental quality incentives programs for implementation cost-sharing. The first tier is less stringent than tiers two or three. The second tier of the plan is called the "regulatory-based encouragement of management practices." The second tier essentially works by allowing polluters to adopt certain managements measures that discourage NPS pollution rather than go through various permitting procedures. Regional water quality control boards may work with landowners and resource managers to waive the adoption of waste discharge requirements (WDRs), a type of effluent limitation, if a polluter adopts certain BMPs. The third tier is called "effluent limitations and enforcement." The effluent limitations may be set at a level where the only realistic manner of compliance is the adoption of BMPs. These limitations are command and control requirements for some activities, including for example WDRs for commercial nurseries, WDRs for selenium for the San Joaquin River, permitted storm water programs, erosion control for Lake Tahoe, and WDRs for dairies. A number of these regulations are derived from California's Porter-Cologne Act, which established the State Water Resources Control Board, along with nine regional boards that are tasked with implementing the Porter Cologne Act. The Act created state water quality standards that the boards must enforce. WDRs are one direct regulation California government agencies use under the Act to regulate NPS pollution. California has a number of other pieces of legislation that address NPS pollution, like the California Coastal Act and the California Environmental Quality Act. Policy instruments and regulatory approaches There are five primary stakeholders involved in NPS water pollution regulation: government agencies, environmental advocacy groups, potentially regulated entities, and the public. Government stakeholders are government agencies responsible for regulating NPS pollution. In addition to