Natural Treatment Site: San Joaquin Marsh

Natural Treatment Site: San Joaquin Marsh

San Joaquin Marsh NTS site

The San Joaquin Marsh is IRWD’s flagship NTS site.  Due to the success of the marsh as a treatment wetland and the benefits it provided to the Upper Newport Bay in removing nutrients, the other NTS sites were developed.  The site has a long history; although it has always been a wetland, it was historically a Duck Club used for hunting, later to be transformed into the treatment wetlands in 1997.  

The removal rates for the marsh are quite impressive, especially in terms of nitrogen removal.  This past year, 62,000 pounds were removed, preventing these nutrients from accumulating in the Upper Newport Bay.  Other nutrients and bacteria saw equally high removal rates as well. 

The marsh vegetation has filled in quickly since planting, and even the last group of treatment ponds (finished in 2002) has grown in well.

 

 Location & Size


Location: 3512 Michelson Drive, Irvine
Size: 320 acres
Tributary Watershed: 75,000 acres
Status: Online September 1997 

 Biological Values


The San Joaquin Marsh has become an important biological asset in the region. It is a stopover for many bird species migrating along the Pacific Flyway. The overall size of the marsh provides on-site nesting habitat for approximately 70 species of birds. Over 280 species have been documented as occurring since 2000.

The adjacent San Diego Creek and its associated riparian habitat also act as a corridor for birds and other mobile wildlife to access the marsh. For a complete list of bird species observed at the Marsh, see the Sea & Sage Audubon Checklist.

Floral diversity is impressive for a site of this size; over 120 species of plants have been documented from the site as well.

 Maintenance


Routine Maintenance Activities:

  • TruGreen LandCare provides routine irrigation and landscape maintenance services at the site. Additional work such as mulch replacement, irrigation repairs, aquatic herbicide application, aquatic vegetation removal, and sediment removal were performed throughout the year.

  • System operations staff performed weekly site inspection, water quality monitoring, and landscape and irrigation maintenance review.

Major Repairs: The North Loop trail was resurfaced to allow users and operations staff easier access to sections of the marsh.
Major Improvements: Currently, the adjacent Michelson Plant is under major renovation which has affected some areas of the marsh.

Latest News

2018-poster-contest-finalists
2018 Poster Contest FinalistsAbout 400 students entered the Water Awareness Poster Contest. Ten students have been recognized as finalists. Their posters move forward for a chance to be featured in the 2019 Water Awareness Poster Calendar published by the Metropolitan Water District of...
ready-set-quake
Ready, Set, QuakeCalifornia is earthquake country and you always want to be ready. IRWD suggests you enroll in the CodeRED® Emergency Alert System to receive updated information in any emergency. Just log on to irwd.com and click “Emergency & CodeRED” in the...
money-saving-tesla-batteries-arrive-at-irwd-s-michelson-plant
Money-Saving Tesla Batteries Arrive at IRWD’s Water Recycling PlantA caravan of 18-wheelers and large hoisting cranes completed delivery on Tuesday of 75 high-efficiency Tesla batteries to the Michelson Water Recycling Plant, where they will be installed as part of Irvine Ranch Water District’s money-saving Energy Storage Program. For those...