As part of an ongoing effort to make content more accessible, LAM will be making select stories available to readers in Spanish.
BY TIMOTHY A. SCHULER
FROM THE MARCH 2021 ISSUE OF LANDSCAPE ARCHITECTURE MAGAZINE.
On August 29, 2005, the world saw what happened when a levee failed. A Category 3 hurricane slammed the Gulf Coast, 169 linear miles of federally constructed levees collapsed, and nearly 80 percent of New Orleans flooded, killing almost 1,000 people, the majority of them African American and over the age of 65. It was a wake-up call not just for New Orleanians but for lawmakers 2,000 miles away in California, who worried about their own state’s intricate system of ancient levees, which hold back the waters of the Sacramento–San Joaquin Delta.
Covering an area the size of Rhode Island, the Sacramento–San Joaquin Delta is an inland delta formed by the confluence of five major waterways, including the Sacramento and San Joaquin Rivers. It stretches from just east of the San Francisco Bay north to Sacramento and south to Stockton and drains more than 50 percent of the state of California. It is also a highly engineered landscape, made up of winding canals, earthen levees, and terraced agricultural fields. Roads follow the sinuous levees, forming what, from the air, appears as a convoluted puzzle pieced together over eons by a deranged dissectologist.
The delta’s present-day morphology is the product of one of the largest land reclamation projects in U.S. history. In the late 19th century, farmers and land speculators drained more than 500,000 acres of wetlands in the delta, using the dredge material—much of it the spoils of industrial gold mining—to build human-made islands. In the 20th century, water conveyance projects such as the California State Water Project further severed the relationship between delta wildlife and its unique hydrology. “There is nothing about the delta that is like what it used to be,” explains Brett Milligan, an assistant professor of landscape architecture at the University of California, Davis, and a cofounder of the Dredge Research Collaborative. “The way water flows through it is entirely different. The channels have been widened; all the dendritic channels have been cut off. There’s no floodplain at all.” (more…)
