July 29, 2009 > Alameda Creek-keeping Fremont above water
Alameda Creek-keeping Fremont above water
By Alyson Whitaker
The Alameda Creek Trail is a popular route for walkers, bikers, and runners living near its path. Nearly 12 miles of unobstructed trail reaches all the way to the bay, with no street-crossings, and makes for a safe and scenic path year-round. The creek is home to a wide variety of wildlife, and construction is underway to allow the re-introduction of the steelhead trout population to the creek. It is also a creek with a long history in the Bay Area.
This waterway is the largest stream in Alameda County, draining all of Livermore Valley through Niles Canyon. Before urban development began, each flood added another blanket of sediment essentially creating the flatlands of the Fremont area. The soil here consists of layer upon layer of sand, silt, clay, and gravel, all deposited by the floodwaters of Alameda Creek.
After World War II, the area around Alameda Creek experienced a building boom; homes and businesses popping up all along the flatlands. With increased development, the natural water flow during the rainy season brought with it a high risk of flooding. Prompted by a flood in 1955 and another in 1958, residents voted to create the Alameda County Flood Control District. A channel was built to control floodwaters and route them to the bay. By 1972, the Army Corp of Engineers had completed construction of the channel. The result was a much larger creek, about 200 feet wide and 10 miles long. Bordered by 20-foot high levees, it was capable of holding much more water than the original creek bed. Because of this largely man-built channel, the natural cycle of flooding in the flatlands of Fremont has been suspended.
Following the levee breakdown that devastated New Orleans in the days after Hurricane Katrina, FEMA (Federal Emergency Management Agency) created the Professionally Accredited Levee Agreement. As part of this agreement, FEMA gave local and state agencies two years in which to evaluate levees within their jurisdiction. Through a process of site-drilling, mapping, and studying the soil and structures, Alameda County Flood Control District is in the process of finalizing the FEMA-mandated survey. Findings and documentation are scheduled to be submitted to FEMA in early August.
Upon the completion and submission of the surveys across the country, FEMA will review findings and results, meet with local flood control agencies, and finalize the flood plain mapping process. The new flood plain maps will indicate areas that are susceptible to flooding. Areas located behind levees will be shaded indicating a possible risk of flooding if a breach of levee were to occur. Homes and structures located within a flood plain are required to carry flood insurance.
To date, the Alameda Creek has functioned as it was designed, and the levees have provided consistent and reliable flood control to the surrounding area since its completion in 1972. There are no known flood plains in the surrounding area. Ongoing studies and regular maintenance continue to ensure that the creek bed and its accompanying trail will provide enjoyment and flood control for years to come.
More information on the Alameda Creek Flood Control District can be found online at http://www.acgov.org/pwa/acfcdweb/web/home.html.