Environmental group Heal the Bay called for stricter protections on the Malibu Creek watershed last week, after a 12-year study it conducted found that much of the watershed fails to meet current water quality standards.
The organization plans to lobby Malibu and other cities in the watershed to adopt low impact development ordinances, reduce sediment, bacteria and nutrient output from agricultural sites in the watershed and increase the volume of water stored and recycled at Tapia Water Reclamation Facility.
“Throughout the Malibu Creek Watershed, streams are polluted and don’t meet current water quality standards, potentially harming the well-being of anyone who comes in contact with this water,” the Heal the Bay study found. “Excess bacterial pollution can cause stomach flu and various infections not only in the watershed itself, but also downstream at public beaches.”
“An Ecosystem on the Brink,” published Friday of last week, assesses the current condition of the 109-square-mile watershed and ways to reverse deterioration throughout the region, which winds its way through the southern edge of Ventura County, northwest Los Angeles County and eventually drains into Surfrider Beach in Malibu.
As part of the study, Heal the Bay monitored water chemistry at a number of sites throughout the watershed, including the Malibu Lagoon. The testing analyzed water nutrients, bacteria, acidity, temperature and dissolved oxygen contents in the watershed.
One of the worrisome findings, the study’s authors said, was that many parts of the watershed are overpopulated with nutrients. While people may naturally be inclined to think of nutrients as a positive force, they can cause too much outgrowth such as algae and harm natural resources, according to Sarah Sikich, who co-authored the study.
“Too many nutrients cause an excess of fertilization,” Sikich said.
Volunteers and staff also spent four years of the study physically walking and mapping more than 70 miles of streams throughout the watershed, which helped identify physical barriers throughout the system. Hard barriers, the study found, cause downstream erosion and habitat loss.
According to the study, 31 percent of the watershed’s stream banks were hindered by some sort of concrete or hard barrier that were likely installed to protect private land but ultimately hastened water flow and downstream erosion in the watershed.
The group advocates for stream protection ordinances that would stabilize stream banks with soft vegetation barriers, as opposed to hard concrete or rock barriers currently common throughout the watershed.
The largest single barrier in the watershed, according to Heal the Bay, is Malibu’s Rindge Dam. The group views the 100-foot structure as a major detriment to the endangered southern steelhead trout that cannot swim upstream to a key migration point.
For Heal the Bay’s recommendations to become reality, though, several municipalities, including Los Angeles County, Malibu, Agoura Hills and Calabasas, have to be on board with the findings.
City Manager Jim Thorsen said Malibu officials had yet to digest the study, but several city representatives planned on attending a public workshop hosted by the environmental organization Tuesday night in Calabasas.
“As we review the data and we hear what information they’re preparing, the city will assess if and how to move forward on it.” Thorsen said. “If it’s something that seems reasonable, then we’d get behind it.”
The workshop was held as The Malibu Times went to press.
The complete Malibu Creek Watershed study is available online at healthebay.org/watershed.