Although Clear Lake is naturally warm, shallow, and eutrophic, there is nothing natural about the explosive growth of aquatic weeds and cyanobacteria (“blue green algae") experienced in recent years. These conditions have been caused by human activities, including streambed alterations, fertilizer runoff and illegal off highway vehicle tracks. Of particular significance, the lake has lost approximately 80 percent of its natural wetlands over the years, wetlands that not only provided superb wildlife habitat but also acted to filter excess nutrients and keep them from reaching the lake.
It is estimated that the Scotts and Middle Creek watersheds on the north end of the lake provide 57 percent of the inflow and 71 percent of the phosphorus loading to Clear Lake.
1400 acres of wetlands below the confluence of Middle and Scotts Creek were “reclaimed” for agriculture in the first half of the 20th century by construction of levees. Never built to a high standard even when new, these levees have deteriorated over time and are now highly prone to failure during flood events. The cost of repair would far exceed potential benefits.
In the meantime the excessive nutrients that pass through the area play a major role in the degradation of Clear Lake water quality. A 1994 Environmental Protection Agency study recommended restoration of the area -- the largest single damaged wetland on the lake -- as a top priority for improving water quality and restoring the ecosystem of the lake to health.
It is estimated that the Scotts and Middle Creek watersheds on the north end of the lake provide 57 percent of the inflow and 71 percent of the phosphorus loading to Clear Lake.
1400 acres of wetlands below the confluence of Middle and Scotts Creek were “reclaimed” for agriculture in the first half of the 20th century by construction of levees. Never built to a high standard even when new, these levees have deteriorated over time and are now highly prone to failure during flood events. The cost of repair would far exceed potential benefits.
In the meantime the excessive nutrients that pass through the area play a major role in the degradation of Clear Lake water quality. A 1994 Environmental Protection Agency study recommended restoration of the area -- the largest single damaged wetland on the lake -- as a top priority for improving water quality and restoring the ecosystem of the lake to health.