Recreational activities in lakes and reservoirs near dams in the Sierra Nevada are a popular, fun summer pastime. With recent fires in California leaving burn scars in some areas, there is an increased chance for debris flows, mudslides and sudden water level changes during rainstorms.
This year, to maintain safety, the public should be on the lookout for weather-related hazards.
National Dam Safety Awareness Day is May 31.
Southern California Edison has worked with local, state and federal agencies and partners to address landscape changes near its reservoirs. The utility used geological surveys, soil examinations and area modeling for debris flows and mudslides to create a response plan.
“We overlaid the burn scar mapping on our infrastructure to assess how our dams and the surrounding environment may be impacted,” said Matthew Muto, SCE engineer in Dam and Public Safety. “That helped us to decide what safety measures to use for debris management and other storm-related issues.”
Two recent dry years have also created drought conditions. Reservoirs and lakes near dams will have lower water levels for downstream recreation. Where people would normally go swimming or boating, there may now be hazards, such as rocks, boulders and debris closer to the surface.
National Dam Safety Awareness Day was established in memory of those who lost their lives in the 1889 South Fork Dam failure near Johnston, Pennsylvania. Dams provide a life-sustaining resource to people across the U.S., and ensuring they are maintained and operated safely is key to sustaining these key infrastructure resources.
“The communities around our dams are outstanding partners. We’re all working together to enjoy the upcoming season while remaining safe,” said Nicolas Von Gersdorff, SCE’s chief Dam Safety engineer and senior manager for Dam and Public Safety.
SCE has implemented several measures to help protect the public and the areas surrounding its reservoirs, including:
- Debris Booms — Catch and control release of debris to prevent it from damaging recreational areas and dam facilities.
- Hazard Tree Removal — Eliminates vegetation that may fall or become unstable in burn scar areas and other key locations.
- Soil Stabilization — Helps make hiking paths, working areas and roads safer and improves water quality in nearby streams. Stabilization includes hydro mulching, sandbags and installation of straw wattles.
- K-Rails and Silt Fencing — Manage debris around power houses and switch yards.
- Drones — Used for inspections so SCE can evaluate hazards in inaccessible areas.
- Interagency Exercises — Conducted to prepare for potential debris flow and high-water flow scenarios.
- Public Outreach — Replacing safety signs destroyed during last year’s Creek Fire. Posting public safety notices as applicable.
- Contingency Planning — If there are significant storms, interagency weather and debris flow modeling will help authorities to restrict roads that may be impacted and, in rare cases, evacuate areas that may be at risk.
Safety Tips
- Visitors should always take the time to be aware of their surroundings, especially in areas near and around burn scars. There may be loose debris, shifting dry sediment and unstable trees — even on a sunny day. Know what is below and above you and always have a path out.
- For those boating or swimming in lakes and reservoirs, be aware you may see sudden shifts in water levels during storms at any time. Determine where the high ground is and how to get there if there is a change in water level. Do not camp in low-lying areas next to water if rain is forecast.
- Pay attention to signs in the area. Signs identify areas that the public should not access for safety reasons and warn of potential changes in water flow. There are some areas where there are early warning sirens that alert the public to move to high ground.
- Research the areas in which you will be recreating — there are kayaking and paddling organizations that provide information about recreational water conditions and hazards (americanwhitewater.org, paddewise.org, paddling.com]. Be aware of your swimming and paddling abilities relative to conditions and types of currents.
Safety Tips Around Dams:
- Never swim near a dam or dive from a dam structure. Dangerous currents can pull you through the dam or against flow structures.
- Never fish, boat or swim immediately below a dam because water levels and flow can change quickly.
- Never moor, tie or anchor your boat immediately below a dam.
- Keep personal watercraft and boats clear of dams and dam structures.
- Stay outside of booms and away from all dam structures.
- Never sunbathe, picnic or camp in an area that may flood because of dam operations
Learn more about dams and dam safety here.
