Natural Treatment Site: Old Laguna

Natural Treatment Site: Old Laguna

Old Laguna NTS site

Old Laguna NTS site has functioned well throughout this year.  It was taken offline only twice to facilitate repairs to the outlet structure and clear vegetation.  There have been no problems with sulfides, however, algal growth in the slow-moving pools continues to be a problem, but not enough to warrant drainage of the site.

Water quality monitoring at the site has shown good removal rates for all nutrients including nitrogen and phosphate; suspended solids and total coliform removals were adequate as well. Selenium removal rates were within the standard range.  

The site is scheduled for maintenance upgrades next fiscal year, including sediment removal near the inflow pool.

 Location & Size

ocation: 16585.5 Laguna Canyon Road, Irvine
Size: 2.5 acres
Tributary Watershed: 231 acres
Status: On line, February 2006

  Biological Values

he site is somewhat isolated, and wildlife values are low.  Additionally, African Clawed Frogs were discovered at the site this year, which may warrant further action, such as draining the site to facilitate removal. The following nesting bird species were observed on the site: Marsh Wren, Bewick’s Wren, House Wren, Mallard, Western Bluebird, House Finch, Black Phoebe, Tree Swallow, Common Yellowthroat, Song Sparrow, American Crow, Greater Roadrunner, Yellow Warbler, Mourning Dove, Yellow-breasted Chat, American Coot, Bullock’s Oriole, Ash-throated Flycatcher, American Robin, Cooper’s Hawk, Red-shouldered Hawk. Additional wildlife observations are planned for next year’s report.  


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: None during this fiscal year, however, the slope along Laguna Canyon Road (which the City of Irvine maintains an easement upon) was excavated in part to install a manhole for a fiber optic cable.  Work on this project will continue into the next fiscal year. In addition, sediment removal at this site is planned for next fiscal year.
Major Improvements: None during this year.

Latest News

IRWD Wins Innovation Award For Energy Storage ProgramThe IRWD Energy Storage Project was recently selected as a winner at the 6th Annual Golden Hub of Innovation Awards by the Association of California Cities - Orange County (ACC-OC). The Golden Hub of Innovation Awards recognizes local agencies, cities and...
IRWD Professionals Assure Water QualityWhen it comes to delivering safe water to our customers, the bottom line is that Irvine Ranch Water District meets or exceeds all state and federal guidelines for drinking water. Ensuring that quality on a day-to-day basis is the primary responsibility...
Posters Chosen for Annual ContestFive posters created by students who attend school in the Irvine Ranch Water District service area were selected for judging in the Metropolitan Water District of Southern California’s “Water is Life” poster contest. IRWD judges selected the posters from among many...