Northern California’s Wild and Wet Winter of 2011
Author: Flood Expert Mick Lopez
There seems to be more wild weather affecting Northern California. In the coastal towns of Santa Cruz and Capitola for the first months of 2011, they have experienced snow storms, flash floods, and even the effects of the Japan tsunami. The first two are somehow related as the ground is totally saturated from all of the rain and rare snow that has been coming down through the winter.
The rains in late March were the latest in a series of storms that swelled lakes, reservoirs and rivers. The Santa Cruz County Office of Emergency services had to issue flood warnings in the Santa Cruz Mountains after the San Lorenzo river began spilling over its banks. The residents of Felton Grove, Paradise Park, Gold Gulch and Capitola Village were ordered to evacuate homes and business. The storm knocked out electricity to 14,000 customers in Live Oak and Santa Cruz.
Some of the most significant damage came one afternoon when a 3-foot flood of water tore through Capitola Avenue and the village. City officials said a storm drain that connected to Noble Gulch Creek between Bay Avenue and Capitola Avenue overflowed, sending water shooting up out of manhole covers and into the streets. Water flooded the Pacific Cove Mobile Home Park next to Capitola City Hall and the police and fire stations, spreading debris, causing a sinkhole and tearing off porches of the mobile homes.
This flood was just another version of two great floods in the past fifty years. In the “Christmas Flood” of 1955, most of the damage occurred within the city of Santa Cruz as the San Lorenzo spilled over its banks. Unprecedented river flooding spread water across the main business district, and demolished hotels, business and trailers along the shore. There were millions of dollars of damage and five people drowned within the city limits. While the San Lorenzo River is a scenic asset to Santa Cruz as it cuts through the city, it can be dangerous after torrential rains.
In January of 1982, there was another great flood, but this affected mostly areas outside of the city of Santa Cruz. The toll from the Santa Cruz County flood included 22 dead, 50 injured, 400 people displaced, 135 homes destroyed, 300 homes damaged, and over $100 million in damages.
Commercial floodproofing in Santa Cruz and Capitola would require a two-pronged approach. For flash floods of less than one foot, this will require quick flood mitigation techniques such as rapidly installable barriers. One example of this would be the easy-to- install PuddlePanel from FloodPanel, the sponsors of this website. For areas that will bear the brunt of a raging river, the best commercial application is to create a solid metal barrier across the face of the building. Two examples of our products that would protect flooding from a river are the “Panel and Post” system, which is less expensive but takes longer to install, or our special “Flood Log” system, which is specially made for faster installation. By having these two commercial-grade aluminum barriers on the outside perimeter, or at least, covering the main openings, the hydrodynamic forces of the rushing water will not break the structural composition of the commercial buildings. In addition, we would suggest that buildings near the river would floodproof the walls with impermeable paint to resist water penetration through bricks, install special sewer line flow control systems, and even consider sump pumps in basements. You have to consider that sometimes the force of the water does not only cause passive water damage inside the building, but may in effect cause the collapse of the structure.