Friday, June 5, 2009

A Meandering Demo(n)-stration on Coyote Creek

On Monday, June 1, the Santa Clara Valley Water District held a "Open House" in the Olinder School Cafeteria to discuss their flood control options with the surrounding neighborhoods. About 100 people showed up over a four-hour period to be given docent-guided explanations of the dozens of wall maps, charts and graphs depicting the 10 or so options that had so far been considered by the engineering staff of the Water District.

Many folks showed up to voice their protest about any plans that included removing homes from the creek banks or putting levees around the park to enhance its function as a flood detention basin. In a separate post, I describe why William Street Park and much of the Coyote Creek park chain was developed for the dual purposes of flood detention and recreation.

Purely by coincidence, the next day, the Water District conducted what may have appeared as a demonstration of what it would look like to remove a house along the creek. The pics and video below was taken by me on Tuesday. What you see is the pile of sticks which used to be the Jaffe home on the 300 block of South 17th Street in downtown San Jose on the west bank of Coyote Creek.

The story of why this home was demolished began a few weeks after the January 25, 1997 flood on the Coyote Creek. After the flood stage had passed, the Water District began releasing water from Andersen Reservoir, located 20 miles upstream, for the next six weeks or so. Once they reached the elevation of their "rule curve" someone ordered the valve closed at the dam and the water level in the creek downtown dropped 2-3 feet almost instantaneously. Without the water column as a buttress, the saturated banks did what gravity demands and began flowing out into the river and everything above it collapsed.

Another home next to and south of the Jaffe's completely tipped dangerously toward the river, and was soon red tagged and eventually demolished also. There was also some bank failure in the back yard of the home north of the Jaffe home as well. The slippage of the bank unfortunately occurred in the middle of the Jaffe home, so part of the house remained habitable for the time being.

Law suits were, of course, filed against both the District and the City. The District used the immediate defense that the sewer in front of these homes was damaged and leaking and was therefore the cause of the bank failure, not the operation of the reservoir. After I was deposed by the attorney for the home owners, the water District's attorney was not too happy that I supported the theory that the bank slipped due to "draw down failure." In response, they shopped around for someone to write them a report refuting this theory and found a Stanford professor that would back them up, for a considerable fee, of course.

The District won the case but never felt too good about it, apparently, for in about 2006, the District offered to buy the Jaffe's home and remove it, as they have now done. This bring the total to five lots on the west bank of Coyote Creek now restored by the Water District to undeveloped parcels between the William Street bridge and the San Antonio Street bridge. The term used by the District (and others) for homes that back up to the creeks is called "encroachment."

Prior to 1950, before the construction of Andersen Dam, large setbacks from the creek banks were the rule, and streets such as Arroyo Way and Brookwood Drive did not exist, in respect for the need for such setbacks. The City General Plan today includes a 100 ft. setback for new subdivisions, but is seldom enforced, especially if the developer claims they will lose many buildable lots that the City should buy in order to "create" the setback.

The District, for years, has been encouraging Cities and the County to not create subdivisions that allowed homes to back up against the creek banks. Streets were encouraged or at least tolerated, even when floodable, as the District could use these paved surfaces for maintenance, while building homes that backed up to the creeks blocked access and created a continuous source of complaints and often litigation.

In 2000, the voters approved a parcel tax by over a two-thirds margin to fund the "Clean,Safe Creeks and Natural Flood Protection Program." This would generate funds for a period of 15 years to begin several flood control projects throughout the County. One of these projects is the Mid-Coyote Creek planning study, which began near the end of 2007 and has progressed to the state which was on display at the Olinder Cafeteria on Monday.

Yesterday, our District 3 Council member, Sam Liccardo, notified the neighborhoods that a task force would be appointed from all the neighborhoods surrounding the mid-Coyote Creek, between East Hedding St. upstream to Hwy. 280. Over the course of the next year, alternatives will be evaluated and recommended for consideration by the District. Congress member Zoe Lofgren also sent a letter to the neighbors that stated that no project would move forward without her endorsement and that of the neighborhood.

Tomorrow, the Water District will conduct a bus tour for those that signed up on the Monday or Wednesday "open house." The tour will start at Andersen Dam and move downstream, following the virtual flood wave through the reservoir and the creek channel below, heading eventually to South San Francisco Bay. This will hopefully help some of the neighbors visualize the daunting task upon the Water District staff to route a flood wave up to 17,000 cubic feet per second through this highly developed metropolis. It will also be a great opportunity to compare the benefits of flood detention to the less popular and more expensive alternatives of channelization.

But even if most of the flooding can be prevented using the existing reservoirs and other detention facilities like Laguna Seca in Coyote Valley and Lake Cunningham next to Eastridge, the meandering of the river bed through downtown neighborhoods will continue to claim homes built adjacent to Coyote Creek and, in time, we will see a repeat of yesterday's demolition and the demonstration of the forces of the earth, constantly at work in this naturally meandering stream bed.

No comments: