Latest update (October 16, 2026)
Still open: Irvine Lake remains open for shoreline fishing Fridays through Sundays, 7 a.m. to 4 p.m., with $5 parking, per OC Parks. OC Parks hasn’t posted a final fishing day, but this weekend (Oct. 16–18) and possibly next weekend (Oct. 23–25) may be the last chances to fish before the drawdown.
Oct. 23 permit hearing: The Santa Ana Regional Water Quality Control Board will consider Tentative Order R8-2026-0042, the Santiago Creek Dam permit, as Item 11 on Oct. 23, 2026. The staff report recommends adopting the order as presented. The board received about 80 public comments raising fish-mortality concerns, including white sturgeon and calls for fish salvage and relocation. Staff consulted the California Department of Fish and Wildlife, which indicated Irvine Lake is a stocked lake and that no endangered fish species were identified as affected; the recommended order does not add a fish-salvage requirement.
Reported drain date: Fishing reports, including Western Outdoor News, say the drawdown starts Oct. 26, 2026, and that the lake may stay dry until about 2030. OC Parks and IRWD have not confirmed that date.
Irvine Lake is still open for shoreline fishing as of October 16, 2026, but a major drawdown is approaching as Irvine Ranch Water District prepares for the Santiago Creek Dam Improvement Project. Supervisor Don Wagner has said IRWD plans to drain the lake in October; OC Parks and IRWD have not posted an official final public-fishing end date. Major dam construction is expected to begin in summer 2027 and continue through approximately 2030.
The work is much more than a renovation of the recreational areas around Irvine Lake. Santiago Creek Dam, which forms the lake, is more than 90 years old, and the project will replace major components of the dam, strengthen the earthen embankment and improve seismic safety and water-storage reliability.
When Is Irvine Lake Closing?
Irvine Ranch Water District is completing site-preparation work in 2026. Orange County Water District has reported that IRWD plans to begin draining Irvine Lake in fall 2026, and Supervisor Don Wagner — in announcing the September 12, 2026, catfish derby — said IRWD would drain the lake in October. That derby has now passed; Wagner framed it as the last Irvine Lake fishing derby for the foreseeable future. Coverage of Wagner’s announcement appeared in California Sportsman. The Santa Ana Regional Water Quality Control Board has scheduled an October 23, 2026, public hearing (9 a.m., Cypress, with remote participation) to consider Tentative Order R8-2026-0042 for the project. The notice says the project will cause up to 162.23 acres of temporary and 3.22 acres of permanent impacts to waters, including vegetation impacts caused by dewatering Irvine Lake. The hearing staff report recommends adopting the order as presented.
IRWD documents describe modifications to the existing outlet tower that will allow the lake to be drained as low as possible before the main dam contractor mobilizes. For that reason, it is more accurate to describe the upcoming work as a major drawdown rather than assume that every part of Irvine Lake will become completely dry.
As of October 16, 2026, shoreline fishing remains available at Irvine Lake Fridays through Sundays from 7 a.m. to 4 p.m., per OC Parks. Parking is $5 per vehicle; OC Parks annual passes are not accepted (since July 1, 2026). Neither OC Parks nor the IRWD Santiago Creek Dam project page has posted an official final public-fishing end date yet. Status can change with weather, red-flag warnings or construction — check before you go.
See our Irvine Lake guide for current fishing hours, rules, parking, maps and visitor information.
How Long Will the Irvine Lake Project Take?
IRWD currently expects major construction to begin in summer 2027, with the project estimated to be completed in 2030. Orange County Water District has described the dam construction as spanning four dry seasons and reported that water will not be retained behind the dam during that work.
- 2026: Site preparation and advance construction activities.
- Fall 2026 (October signal): Supervisor Don Wagner said IRWD would drain Irvine Lake in October; OC Parks has not published an official final fishing end date.
- October 23, 2026: Santa Ana Water Board public hearing on the project permit (Tentative Order R8-2026-0042, Item 11); staff recommend adoption as presented.
- Summer 2027: Major Santiago Creek Dam construction is expected to begin.
- 2027–2030: Major dam construction period.
- 2030: Current estimated project completion.
Why Is Irvine Lake Being Drained?
The drawdown is necessary so crews can complete the Santiago Creek Dam improvements safely. The dam was originally constructed in 1933, creating Irvine Lake. IRWD began a comprehensive assessment of the dam in 2017.
According to IRWD, the engineered earthen dam remains operational but could be made safer. The assessment also determined that the existing outlet tower and spillway are reaching the end of their useful lives and should be replaced and upgraded to modern seismic and dam-safety standards.
What Work Will Be Done at Santiago Creek Dam?
The Santiago Creek Dam Improvement Project includes several major improvements:
- Replace the existing outlet tower that controls water entering and leaving Irvine Lake.
- Construct a new spillway designed to current seismic and safety standards.
- Strengthen the earthen dam embankment.
- Improve control of water flowing into and out of the reservoir.
- Restore reservoir storage capacity.
- Improve long-term seismic performance, dam safety and water reliability.
Advance work also includes modifications to the outlet tower, a temporary water line along Blue Diamond Haul Road, an isolation valve for the Irvine Lake Pipeline, demolition of the former dam keeper’s residence and removal of a floating boat dock along the lake’s western shoreline.
Why Irvine Lake Is Important to Orange County
Irvine Lake is best known locally for fishing, but recreation is not its primary purpose. The reservoir stores water for surrounding Orange County communities and supplies water used by the Baker and Howiler treatment plants. IRWD says those facilities collectively provide water to approximately 85,000 homes in Central and Southern Orange County.
The project is also intended to restore additional reservoir capacity, allowing Irvine Lake to capture more local rainwater and helping reduce dependence on imported water.
What Does the Project Mean for Villa Park?
Irvine Lake has a direct connection to Villa Park’s water supply. Serrano Water District, which serves Villa Park and a small portion of Orange, owned 25% of Irvine Lake for more than 90 years. On January 15, 2025, Serrano transferred its ownership of Irvine Lake and Santiago Creek Dam to Irvine Ranch Water District.
Serrano Water District continues to use local surface water stored in Irvine Lake as part of its water supply. The ownership transfer was made in exchange for a new backup water-supply connection between Serrano and IRWD, providing another connection to the regional water system.
Will Irvine Lake Fishing Close?
The planned drawdown and dam construction are expected to affect recreation at Irvine Lake. Supervisor Don Wagner has indicated an October drain and described the September 12, 2026, catfish derby as the last for the foreseeable future — but an official final fishing date and detailed recreation closure schedule have not yet been posted by OC Parks or on IRWD’s project page. Do not treat the October signal as a hard public-closure date until those agencies publish one. Shoreline fishing is currently managed by OC Parks, while IRWD manages the reservoir and dam project.
Because the construction schedule and lake conditions can change, anglers should check the OC Parks Irvine Lake page for fishing access and the IRWD Santiago Creek Dam Improvement Project for construction updates.
Will Irvine Lake Reopen?
The project is intended to keep Santiago Creek Dam and Irvine Lake operating safely for decades to come, not permanently eliminate the reservoir. IRWD has described the improvements as preparing the facility for another 100 years of operation.
What has not yet been announced is a specific date for the return of shoreline fishing or what recreational access will look like after construction. Those details should become clearer as the project progresses.
Irvine Lake Project Updates
We will update this page as IRWD and OC Parks release additional information about the Irvine Lake drawdown, fishing closure, construction schedule and reopening. For general lake information, maps and current fishing rules, visit our Irvine Lake fishing and visitor guide.