Federal and state laws regulate water quality to protect these beneficial uses. Water quality standards specify the conditions that water must meet to protect these particular uses. Measuring lakes and rivers against water quality standards tells us which bodies of water need to be restored and protected, and determines how to limit pollutant emissions from public and private businesses. Developing, implementing, and enforcing water quality standards is costly for state agencies, local governments, businesses, and taxpayers. But the standard benefits the state by protecting Minnesota's lakes, rivers, and streams, as well as the ecosystem services that Minnesotans hold dearly. Rehabilitation of water systems affected by contamination is often a time-consuming and expensive process. Preventing water quality deterioration is generally more cost-effective than reversing it after it has deteriorated. Discharges to rivers and lakes can alter water quality for downstream users. Pollutants discharged into state waters may need to be removed or treated by downstream drawers. Water quality standards limit the amount of solids such as dirt and sand that enter state waters. The U.S. Army Corps of Engineers is tasked with keeping both the Port of Duluth and the Mississippi River navigable, preventing sediment erosion and saving Army units additional dredging and costs. Wetlands and riparian forests provide natural water purification, keep wildlife and their habitats healthy, and promote recreation and tourism. Treating the water that enters wetlands and rivers maintains the resilience of water bodies and allows them to recover easily from pollution. Regional and global concerns about wetlands and water quality. Real estate prices for land on or near lakes and rivers often include a premium for high water quality, especially water clarity. The analysis found that a one-meter improvement in water clarity in 37 northern Minnesota lakes would increase the lake property value of these lakes by millions of dollars. The U.S. Reporting Fish and Wildlife Service and the U.S. Census Bureau estimate that Minnesota spent her $3 billion on fishing and wildlife watching in 2011. Many academic studies show increased recreational use of lakes with improved water quality. Water quality standards also protect iconic locally grown products such as wild rice and pollock. Some pollutants pose risks to human health. Water quality standards protect human health and avoid healthcare costs, lost productivity and even loss of life. Minnesotans cherish their famous lakes and the time they spend near them. Spiritual and religious practices of some residents are associated with water. Poor water quality not only reduces the clarity of lake water, but it also promotes the growth of unsightly algae, which can make swimming uncomfortable or unsafe. Clean water is a public good, and the Clean Water Act requires it to be provided to public bodies based on taxpayer contributions. The MPCA intensively monitors eight watersheds each year, reaching all 80 watersheds in the state on a 10-year cycle. The agency also reports on water quality issues and what needs to be done to clean up streams and lakes and protect those at risk of degradation. Additionally, the MPCA is responsible for setting water quality standards and incorporating them into state regulations, which can be a long and tedious process. Next, government agencies must work to enforce the regulations.