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Pacific Ocean breakwaters at Agua Hedionda, with the Encina power plant in the background. Photo by Joe Wolf
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Poseidon Water new steward of Agua Hedionda Lagoon

CARLSBAD — A new steward is taking on Agua Hedionda Lagoon.

Poseidon Water, which owns the Carlsbad Desalination Plant, has taken over the responsibilities of the lagoon from NRG Energy, which owned the now retired Encina Power Station and new peaker plant off Carlsbad Boulevard and Cannon Road.

One responsibility Poseidon Water will continue is periodic dredging of the lagoon, which removes sand and sediment build and allows the lagoon to thrive.

The removal of the material brings clearer pathways for ocean water to circulate, maintaining the sensitive ecosystem.

In addition, the San Diego Regional Quality Control Board approved last week a project from Poseidon to upgrade the intake pipes and pumps.

Smaller screens will also be installed to protect fish from being sucked into the pipes.

“We will be implementing new technology and intake,” said Jessica Jones, communications director for Poseidon Water. “It will have 1-millimeter screens and a special fish protection program that complies with the ocean plan for the state of California.”

The Carlsbad Desalination Plant uses the old power plant’s intake and outfall facilities for the desalination process.

With the decommissioning of Encina Power Station, the desalination plant is modernizing existing intake facilities to provide additional environmental enhancements to protect and preserve the marine environment.

The upgrades will also increase the plant’s daily capacity, from about 54 million gallons of seawater per day to 60 million.

The desalination plant generates 10% of San Diego County’s potable water supply. Jones said construction will begin later this summer with completion in 2023.

Also home to the lagoon are the YMCA Aquatic Park, Carlsbad Aquafarm and Hubbs-SeaWorld Fish Hatchery, which rely on dredging to keep the lagoon deep enough for those entities to perform their functions.

The lagoon covers more than 400 acres of marine, estuarine and wetlands habitat teeming with hundreds of fish, invertebrate and bird species.

Dredging is “historically” done every other year, Jones said, although storms, tidal flows and other considerations are analyzed yearly before dredging is conducted.

Sand from dredging is used to replenish Carlsbad State Beach. Dredging keeps sand from blocking the flow of ocean water in and out of the lagoon and maintains its tidal circulation, which is needed to maintain a healthy marine ecosystem and support extensive recreational uses and sustainable aquaculture.

The deal is for 30 years, Jones said. At the expiration of it, the San Diego County Water Authority may take over stewardship, she said.

“The Agua Hedionda Lagoon Foundation has been dedicated to providing direct access to nature while ensuring the environmental protection of the lagoon,” said Lisa Cannon-Rodman, chief executive officer of the Agua Hedionda Lagoon Foundation. “We are thrilled that Poseidon Water will continue in these efforts and can confidently say that the community will continue to experience the splendor of this unique environment for many years to come.”

The Carlsbad facility employs 100% carbon neutral desalination technology, making it the first major infrastructure project in California to eliminate its carbon footprint.

Poseidon will also do the same at its proposed Huntington Beach Seawater Desalination Plant.