Growing cities, overuse of fertilizers and factory wastewater have degraded China's water supplies to the extent that half the nation's rivers and lakes are severely polluted. China aims to spend $850 billion to improve filthy water supplies over the next decade, but even such huge outlays may do little to reverse damage caused by decades of pollution and overuse in Beijing's push for rapid economic growth. Photo: Fishermen row a boat in the algae-filled Chaohu Lake in Hefei, Anhui province, June 19, 2009. (Photo by Jianan Yu/Reuters)

Renee LeGrand, of Foothill Ranch, Calif., takes a picture among wildflowers in bloom Monday, March 18, 2019, in Lake Elsinore, Calif. About 150,000 people flocked over the weekend to see this year's rain-fed flaming orange patches of poppies lighting up the hillsides near Lake Elsinore, a city of about 60,000 residents. The crowds became so bad Sunday that Lake Elsinore officials closed access to poppy-blanketed Walker Canyon. By Monday the #poppyshutdown announced by the city on Twitter was over and the road to the canyon was re-opened. (Photo by Gregory Bull/AP Photo)

Female bodybuilder Joanne Caldwell competes during the IBFA British Finals Night of Champions contest at the Federation Brewery in Gateshead, Britain on October 22, 2023. (Photo by Lee Smith/Reuters)

Aerial view of a boat working in the green water of Taihu Lake covered by blue-green algae, Wuxi city, Jiangsu province, China on May 23, 2018. (Photo by Imaginechina/Rex Features/Shutterstock)

A train drives along a field at a salt production site at the Sasyk-Sivash lake near the city of Yevpatoria, Crimea, November 14, 2017. A saltwater lagoon known as Lake Sasyk-Sivash on Ukraine's Crimea peninsula is the source of a rare resource: pink salt. The mineral is tinted by tiny algae that produce the pigment beta-carotene. Each autumn, seasonal workers collect thousands of tons of pink salt for processing and export. (Photo by Pavel Rebrov/Reuters)

Luxury buildings are reflected in front of houses at a lake dwelling also known as or palafitte or “Palafito” in Recife, Brazil, March 1, 2016. Zika has spread most rapidly in the urban squalor of Brazil's northeastern coastal cities like Recife. (Photo by Ueslei Marcelino/Reuters)

Kia Vue of St. Paul sports long nails at the Minnesota Hmong New Year celebration Saturday, November 29, 2014, at the Saint Paul RiverCentre in St. Paul, MN. The annual Minnesota Hmong New Year celebration will be held at the Saint Paul RiverCentre November 28–30. Hmong New Year has a deep cultural significance to the Hmong community. It is a celebration of accomplishments during the past year and a time to welcome a new beginning. (Photo by David Joles/Star Tribune)

Dominic Bergamin, left, a new Vatican Swiss Guard, is is kissed by his wife Joanne, prior to a swearing-in ceremony, at the Vatican, Wednesday, May 6, 2015. The ceremony is held each May 6 to commemorate the day in 1527 when 147 Swiss Guards died protecting Pope Clement VII during the Sack of Rome. (Photo by Ettore Ferrari/AP Photo/Pool Photo)