A study of the Arroyo Seco ecosystem has regained momentum thanks to a new motion introduced by Los Angeles County Supervisor Kathryn Barger.
Initiated in 2005, the Los Angeles County Flood Control District entered into agreement with the United States Army Corps of Engineers (Army Corps) on a joint effort for the Arroyo Seco Ecosystem Restoration Feasibility Study. However, the study faced a series of logistical hurdles and funding challenges. In 2017, due to a lack of federal funding, the Army Corps ultimately halted its work on the study and more recently indicated that they will not resume this effort.
Experts from the Los Angeles County Flood Control District stand ready to move forward with the Arroyo Seco Ecosystem Restoration Feasibility Study, which will identify essential improvements to the channel, maximize ecosystem restoration, and ensure flood protection for surrounding communities.
“This study is crucial to the future of the Arroyo Seco and its neighboring communities,” Supervisor Kathryn Barger said. “Once completed, the study’s results will be a blueprint that guides our County’s efforts to both restore the tributary’s ecosystem while enhancing flood protection to the Los Angeles County residents who rely on it.”
The study will focus on the nine-mile stretch between Devil’s Gate Dam and the Arroyo Seco’s confluence with the L.A. River. It will consider channel and bank improvements, as well as alternatives for habitat restoration and biological diversity to reduce flood risk, increase local water supplies, and protect water quality.
The Arroyo Seco is a 22-mile tributary of the Los Angeles River draining an area of 47 square miles, including the Angeles National Forest, and portions of the cities of La Cañada Flintridge, Los Angeles, Pasadena, South Pasadena, and the unincorporated community of Altadena.
Due to the large swaths of publicly-owned land adjacent to the channel, the Arroyo Seco offers excellent opportunities for multi-benefit projects that originate with water capture and purification by using Measure W funds. That water can then be used for a variety of purposes, such as cleaning aquifers and watering surrounding greenery at parks and other public spaces.
Supervisor Barger’s motion will terminate the agreement with the Corps and empower the Los Angeles County Flood Control District to expedite the implementation of the study. A working group consisting of cities within the Arroyo Seco Watershed and the Raymond Basin Management Board will support the efforts outlined within the study.
The motion will be voted upon by the Board of Supervisors tomorrow, during their March 6 meeting.