Skip to content

Los Angeles River Quality

Kayaking in LA River

The Mountain Recreation and Conservation Authority (MRCA) operates the recreation zones on a seasonal basis in cooperation with the City of Los Angeles, the County of Los Angeles, and the Army Corps of Engineers. There are two segments of the Recreation Zone: the 2-mile Sepulveda Basin River Recreation Zone and the 2.5 mile Elysian Valley River Recreation Zone. Both Recreation Zones are open sunrise to sunset daily for walking, fishing, and kayaking from Memorial Day to September 30 every year. For maps and guides and more information on the Recreation Zones see www.lariverrecreation.org.

LA Sanitation staff sample and test water twice a week at three locations in each Recreation Zone, corresponding to the beginning, middle, and end of each zone. Samples are tested in a laboratory for the presence of E. coli bacteria, and for each sample a resulting MPN (Most Probable Number) per 100 milliliters (mL) is determined. The bacteria results at each location are compared to State of California water quality standards for water contact recreation (REC-1 and Limited REC-1) to determine if the water quality, in each Recreation Zone, is suitable for recreational activities. Based on the bacteria levels found, the status of each recreation zone is determined and displayed on the table below according to the following color code:


Color Code Description
GREEN - OPEN Water quality is suitable for recreational activities, but swimming in the river is still prohibited. Test results indicate bacteria levels lower than 235 MPN, the limit for REC-1.
YELLOW - CAUTION Users should exercise increased caution. Test results indicate bacteria levels between 235 MPN (REC-1) and 576 (Limited REC 1) at one or more of the sampling sites located in the recreation zone or above 576 at only one of the sites.
RED - CLOSED This LA River Recreation Zone is not suitable for recreational activities. Test results indicate levels exceeding 576 MPN (Limited REC-1) at two or more of the sampling sites located in the recreation zone. A Closure Advisory will be issued by the City of Los Angeles and the MRCA will close the recreation zone and post closed signs. The recreation zone will stay closed until further bacteria testing show that the zone is once again suitable for recreational activities.


The status of each Recreation Zone is based on the latest bacteria results, but bacteria levels in urban waters can be highly erratic and dependent on a multitude of human and non-human sources. Since elevated bacteria levels can occur at any time in the river, you should always follow these safe practices in order to minimize your risk of getting sick.

  • Avoid/Minimize water contact
  • Wash your body with soap and water if you contact the water
  • Do not drink the water
  • Contact your health care professional if you become ill after water contact

Los Angeles River Watershed Unregulated Swim Sites

People Enjoying the water at a LA River Watersed Unregulated Swim Site
Swimming and wading at freshwater sites located in the Los Angeles River Watershed is popular, particularily during the summer months and on holiday weekends. This is especially true for sites located in the Angeles National Forest such as Sturtevent Falls, Hermit Falls, Switzer Falls, and Eaton Canyon. These sites are unregulated and lack lifeguards, as well as restroom facilities found at regulated sites. Despite the popularity of these sites, little was known about the levels of bacteria at the swimming sites until the Los Angeles Rivershed Watershed Monitoring Program (LARWMP) was started in 2009 by the Cities of Los Angeles and Burbank along with its partners, such as Council for Watershed Health and Aquatic Bioassay and Consulting Laboratories. Since 2009, LARWMP has monitored bacteria levels at the unregulated swim sites from Memorial Day to Labor Day to help build a better understanding of the water quality and inform the public about the health risks at these popular recreation sites. LARWMP samples and tests for E. coli, at each site, five times a month and compares the bacterial levels found to the water quality standards for water contact recreation (REC-1) established by the State Water Resouces Control Board (SWRCB) and Regional Water Quality Control Board (RWQCB). Bacterial levels above the REC-1 standard means you have a higher chance of getting sick, especially if you do activities where swallowing of water is reasonably possible, such as swimming with your head underwater.

The table below has the most current E. coli bacteria levels found at each unregulated swim site tested by the City of Los Angeles Environmental Monitoring Division. Concentrations of bacteria that exceed the REC-1 water quality standard for water contact recreation of 235 MPN/100mL are displayed in red to warn you that you are at a higher risk of getting sick if you swim at these sites.


Bacteria results from previous years at the unregulated swim sites along with more information about the Los Angeles River Watershed Monitoring Program can be found on the Council for Watershed Health website.

Water quality information for additional swimming areas, both salt and freshwater, can be found on the following websites:

LA County Department of Public Health

Heal the Bay

•    Beach Report Card
•    River Report Card

LA Water Keeper

•    Swim Guide

Los Angeles River Watershed Safety

Recreational activities along the LA River Watershed offer an opportunity to explore the region’s unique geography and biodiversity. When enjoying these recreational opportunities, there are important precautions you can take to ensure a safer experience.

  1. Check Water Quality Monitoring Data – Before you recreate, check the most recent water quality results available on this website or the websites listed above. Once you are informed, you can decide for yourself what level of risk you are comfortable with.

  2. Be Safe When You Recreate – Swallowing water with high concentrations of bacteria may result in gastrointestinal illness and wading may cause rashes and eye, ear and skin infections. To help minimize risk at all recreation sites:
    • Avoid swimming during and within 72 hours of a rain event
    • Avoid water contact if you have an open wound
    • Obey all regulatory signs (Park and US Forest Service, MRCA, City and other government signs)
    • Avoid water contact if you immune system is compromised (small children and the elderly are at a higher risk of contracting illnesses)

  3. Help Keep the Watershed Clean – The fecal bacteria that enter the waterways may originate from both human and animal sources. You can better protect our water quality and ensure recreational sites are safe for visitors by:
    • Not entering the water if you have/had diarrhea in the last two weeks
    • Cleaning up after your pets no matter where you are! Bacteria from fecal matter, such as pet waste, can wash into our rivers and streams
    • Using restroom facilities before visiting a recreational site
    • Putting trash in appropriate receptacles, especially trash that can introduce fecal waste into streams (diapers, pet waste, toilet paper)
    • Keeping an eye on children in swim diapers and changing them regularly

Remember that the LA River Watershed is home to many plants and animals which are unique to the region, and depend on food and habitat found near the river. Be a good watershed steward by throwing away trash, and respecting the diverse habitats found along the rivers and streams of the watershed.