The city of Temecula has approved a memorandum of understanding with five other local agencies and Marine Corps Base Camp Pendleton to create a new water monitoring program for the Santa Margarita River estuary.
Temecula, along with Murrieta, Wildomar, the counties of San Diego and Riverside, the Riverside County Flood Control and Water Conservation District and Marine Corps Base Camp Pendleton, will partner to keep track of expected improvements in water quality in the Santa Margarita River estuary through 2024.
The Santa Margarita River is formed at the confluence of the Temecula and Murrieta creeks southeast of Old Town Temecula.
The California Regional Water Quality Control Board, San Diego region has had the Santa Margarita River’s estuary, north of Oceanside, on a list of water-quality limited waterways since 1986 due to eutrophic condition, meaning excessive greening like algal blooms has limited the oxygen supply in the estuary, impacting fish life.
According to a city staff report, studies conducted since the listing have shown the conditions are caused by high amounts of nitrogen and phosphorous — which can get into the water as a result of urban and agricultural runoff.
The U.S Clean Water Act requires total maximum daily loads, which are the maximum amounts of runoff that can get into a waterway without creating poor water conditions, to be assessed for waterways listed as water-quality limited.
The San Diego Water Board issued an investigative order in 2006 for to storm sewer system owners in the Santa Margarita watershed to gather monitoring data to assess total maximum daily loads, and each of the jurisdictions entered into an agreement to accomplish the monitoring, which confirmed the impairment of the estuary was due to eutrophication.
In 2012, as a follow-up effort, each of the jurisdictions along with the San Diego Water Board established the Santa Margarita River Watershed Nutrient Initiative Stakeholder Group to implement supplemental monitoring and studies to answer technical questions for developing targets for improving water conditions.
According to reporting from that group, discharge requirements implemented in 2016 are expected to restore water quality in the Santa Margarita River estuary to appropriate levels.
In May, the San Diego water board directed jurisdictions along the Santa Margarita River to continue to assess the condition of the river’s estuary and evaluate the linkage between water condition and implementation of discharge requirements.
The total estimated cost of the partnership is about $1.5 million. Temecula’s share is expected to be about $320,000, and its first payment will be required in the upcoming 2020-2021 fiscal year.
Will Fritz can be reached by email at firstname.lastname@example.org.