Redondo Beach's Seaside Lagoon Is Giving Up the Ocean to Stay Open

"It changed it from Seaside Lagoon to a pool; from nine feet deep to five feet, saltwater to fresh. It takes it from Thanksgiving all-the-fixings to meat and potatoes." Harbor Commission chair Ryan Ableman said that in mid-September, the night before the Redondo Beach City Council voted to send the lagoon's redesign to the California Coastal Commission anyway.

His complaint is accurate. The council's plan replaces seawater with potable water, swaps the sand bottom for concrete with a shallow sand play area, and cuts the deep end to 5 feet. The trade-off has a history behind it. The ocean water that makes the lagoon feel like the ocean has caused most of its trouble for decades. The plan gives up the salt water in exchange for a lagoon that can stay open.

The Warm Water Came Through a Power Plant

Seaside Lagoon opened in the early 1960s as a modern version of Redondo's saltwater plunge from 1908. The opening year varies by source. A 2021 Daily Breeze story says 1960, while the paper's 2026 coverage and Easy Reader both say 1962.

What set it apart was the temperature. The lagoon draws water through seafloor intake pipes first used by the AES Redondo power plant. In 2021 the Daily Breeze reported that when the plant was running, that water passed through the turbines before reaching the swimming area, which warmed it. So the warm salt water families remember came from the plant's equipment, not from any design for the lagoon.

The city's own description of the system is a lot of work for a summer swim spot. Water is pulled from beyond the breakwater at about 50 feet deep, piped under the street, chlorinated as it comes in, and dechlorinated before it goes back into the harbor.

Every Gallon Going Back Into the Harbor Is Regulated

The water going out has always been the problem. Discharge into King Harbor is regulated by the Los Angeles Regional Water Quality Control Board, and those rules have threatened to close the lagoon several times. In 2010, Mayor Jim Light recalled, the lagoon faced closure over potential fines in the billions of dollars, and the community rallied to save it.

The fines did not end then. Elizabeth Hause, the city's waterfront and community services director, said the city has collected more than $900,000 in water board fines over the past couple of decades because of discharge problems and aging infrastructure. Her explanation of the city's approach puts the whole redesign in one sentence:

"Instead of paying the fines, we want to implement a water board-approved project in lieu."

That changes how the switch to potable water reads. It is the city's answer to a regulatory problem that has cost money and repeatedly threatened the lagoon. Staff plan to replace the saltwater treatment system with a closed-loop filtration pumping system.

What the Council Sent to the Coastal Commission

Here is how the approved Phase 1 compares with the lagoon locals know, based on Daily Breeze and Easy Reader coverage from September 2026.

• Water: Seawater drawn from beyond the breakwater becomes potable water in a closed-loop system.
• Bottom: A full sand-bottom pool becomes a concrete swimming area with a separate shallow sand area for play.
• Depth: The deep end drops to 5 feet. Hause put the old depth at 10 feet and Ableman said nine, so either way the new deep end is about half as deep.
• Features: A new water slide, a fountain and splash features.
• Lap swimming: Buoys mark lanes in the deeper end. That replaces the standalone lap pool in earlier plans.
• Shade and landscaping: A luau shelter and new plantings.

The engineers also added a pressure-release valve system at the bottom of the lagoon after the Harbor Commission objected that the design didn't account for sea level rise. City Manager Mike Witzansky said the city could raise the bulkhead later.

Why the Bigger Plan Was Dropped

The trimmed design upset people partly because they had already approved a larger one. In 2024, the City Council and Harbor Commission signed off on a phased concept with a two-story lifeguard and operations building, a separate lap pool, and fire pits and barbecue areas meant to keep the site busy year-round.

That vision was a concept, not a construction-ready design. After engineering and regulatory review, staff found the first phase alone would cost more than $16 million. In April 2026, the council told staff to go ahead with the smaller scope.

The Harbor Commission saw that scaled-back plan for the first time at a special meeting on Aug. 25 and voted 7-0 to ask the council to pause. Commissioner Roger Carlson said the commission still backed the 2024 version "with salt water, with greater water depth, a sand bottom and amenities which support 365-day activation." Commissioner Leslie Chrzan argued that the ocean-like features, the sandy bottom and the deep water are what make the place unique.

The council voted unanimously to submit the coastal development application anyway. Light said, "This is the closest we've ever gotten to doing something to revitalize the facility." The city also says it is starting to look for funding for later phases, so fire pits and other extras are deferred, not ruled out.

The Summer That Just Ended Might Be the Last of the Old Lagoon

The lagoon is closed for the 2026 season. Its daily hours this summer were 10 a.m. to 5:45 p.m., and the season was scheduled to run from Saturday, May 23, through Labor Day, Monday, Sept. 7. Admission was $10 for adults and $8 for ages 2 to 17. A season pass cost $90 for one person or $190 for a family of four. One Last Splash, promoted as an end-of-summer beach bash, was set for Aug. 30, a party with music, food trucks and kids' activities included with regular admission.

That summer could be the last one with the salt water. Easy Reader reported that if the Coastal Commission approves the plan, construction is expected to start in 2027. The city's stated goal is to finish before the 2028 Summer Olympics.

What Hasn't Been Decided Yet

Several questions that matter to anyone planning next summer around the lagoon are still open as of early October 2026:

1. When the Coastal Commission will hear the application. The city's next step is getting a coastal development permit, then preparing construction plans and hiring contractors. No hearing date has been reported.
2. Whether the lagoon opens in summer 2027. None of the coverage says whether construction will take out the 2027 swim season. No start month has been published.
3. What happens with the $10 million state grant. The money was in the state budget Gov. Gavin Newsom signed in July 2021. The Harbor Commission asked the council to seek an extension. No report confirms that one was requested.
4. How later phases will be paid for. The city says it has started that process, but no amount or timeline has been announced.

The lagoon has also been drained each year since 2019 for BeachLife Festival stages, a reminder that it gets used well beyond swim season. The approved plan keeps the slide, the sand, the lap swimming and the location. It drops the seawater, which is the main reason the lagoon has nearly closed before.

If you live near King Harbor and want to know how projects like the lagoon redesign could affect the waterfront around your home, Lisa Moule Realty follows each step as it goes through City Hall and the Coastal Commission. Schedule your South Bay consultation and we'll go over what's changing near you.

This article is general information, not legal, tax or financial advice. Consult a qualified professional about your situation.