When the largest farm-to-city water transfer was approved in 2003, the state of California gave itself a 15-year period to find a solution to the receding Salton Sea waterline — an environmental disaster waiting to happen. Those 15 years are up. The mitigation water the Imperial Irrigation District was obligated to divert to the Salton Sea has come to an end, and it’s expected the lake’s receding water rate will speed up starting this year, increasing the risk of developing respiratory diseases through the Imperial and Coachella valleys.