Laguna Lake has a major sediment buildup problem, and it might finally get some long-overdue relief from the city of San Luis Obispo with a $10 million dredging project.
On Sept. 20, the SLO City Council voted unanimously to direct city staff to develop a plan in collaboration with MNS Engineers to dredge up to 85,000 cubic yards of sediment from the center of the lake and devise a management strategy to limit sediment buildup in the future.
Decades of sediment deposits in the lake has led to “decreased water quality and aquatic habitat functions, as well as diminished aesthetic and recreational values associated with the lake,” a Sept. 20 staff report read.
“[At the current sedimentation rate] we can expect to see dramatic changes in the next 20 years,” said Bob Hill, the SLO city natural resources manager. “A land bridge will form from the north to the south side.”
Hill presented a variety of dredging projects the council could choose from, differing in the size and scope, the type of technology used, the disposal method, and the disposal location.
City staff recommended the council go with either hydraulic or cyclonic dredging equipment, a mechanical de-watering technique for the sediment, and disposal of the sediment at Cold Canyon Landfill. The City Council agreed with city staff’s recommendation.
The next steps are to develop full-fledged plans for the project, which after approval, will go out for competitive bidding.
Funding options for the project include grants, loans, money from the general fund, and forming a special district to increase property taxes on houses near the lake.
Some residents near the lake took offense to the notion they should pay more than the rest of the city to rehabilitate the lake. Others supported that idea. A community advisory committee may form to discuss the project as it moves forward.
Sedimentation became an issue for the lake in the 1960s after the city diverted nearby Prefumo Creek to flow into Laguna. The city has discussed the possibility of dredging the lake since major storms in the ’60s and ’70s produced significant sediment buildup.