Fire damage to SLVWD facilities
Before and after satellite images of area of CZU Fire
SLVWD facilities on the eastern side of Ben Lomond Mountain that collect, transport, treat and store surface water were severely damaged by the CZU fire. Surface water accounted for about 50% of the District’s water supply before the fire, the remainder being supplied by groundwater from wells. Following the destruction of the surface water intakes near the city of Boulder Creek, demand cannot be met with surface water alone; the District is relying on the Olympia wells (east of Boulder Creek, outside the burn area) to supply its customers in its North system (Ben Lomond, Brookdale, and Boulder Creek).
Creek water intakes near Boulder Creek
Water intakes on Foreman, Peavine, Sweetwater, and Clear Creeks, which drain into Boulder Creek and the San Lorenzo River near the town of Boulder Creek, were destroyed in the fire. A total of 7.5 miles of raw water supply lines, including 5 miles along the east slope of Ben Lomond Mountain transporting water from creek intakes to three large storage tanks and the Lyon water treatment facility near Boulder Creek.
Lyon facility storage tanks and water treatment plant
Treated water lines between the three major tanks at the Lyon facility were burned. The three tanks did not burn because they are made of steel. Replacement of the burned HDPE pipelines between the treatment facility and the three tanks with buried iron pipes began, but it was discovered that two of the tanks were contaminated by back-siphoning of super-heated gases and soot when the HDPE pipelines burned and water drained from the tanks, depressurizing the system. The tanks are presumed to be contaminated by VOCs (tests underway), and, if so, will require blasting to remove the contamination followed by recoating. Thus about 45% of the District’s water storage capacity is unusable at this time.
The Lyon water treatment plant was not damaged by the fire. SLVWD staff shut it down before the fire reached supply lines; hence it is not contaminated. Emergency restoration of the Foreman Creek surface water intake is moving forward because it is important for the integrity of the water treatment plant for it to not lie idle. Foreman Creek was chosen because of all the District’s surface water sources, it produces the largest volume.
An arborist determined that there are serious hazards around the Lyon facilities and access roads from falling burned and smoldering trees, some of which are still burning in their root zones. Many trees will have to be removed, though this has the benefit of creating more defensible space for the future.
Damaged but repaired smaller tanks
Several smaller tanks at Riverside Grove, Eckley, and Blackstone Drive were destroyed along with their associated pumps and utilities. Replacement tanks were a challenge to install due to steep terrain.
The raw water supply line from Bennett Springs to the small tank in the Fall Creek drainage west of Felton burned, but a temporary fix was implemented. The water intake on Fall Creek in Felton is outside the burn area, and was undamaged.The emergency intertie with the South (Felton) system is operational, supplying water from Fall Creek through the District’s Felton Kirby Street Water Treatment Plant.