Time is running out in last-ditch effort to save everything swimming in Irvine Lake
BY MIKE STEVENS
IRVINE – For decades, Irvine Lake has served Orange County anglers and outdoor enthusiasts, but a major transformation is underway. The Irvine Ranch Water District (IRWD) is preparing for a significant drawdown of the lake to accommodate the upcoming Santiago Creek Dam Improvement Project.
It’s another case of a popular fishing lake with residential water storage as its primary purpose, which is nothing new, especially in the west. The reservoir supplies water to roughly 85,000 Orange County homes.
Santiago Creek Dam is over nine decades old. Following an assessment that started in 2017, IRWD identified critical needs to modernize the facility. The multi-year project will replace the aging outlet tower and spillway, strengthen the earthen dam embankment, and boost earthquake resistance. Additionally, the upgrades will restore lost reservoir storage capacity, enabling the capture of more local stormwater runoff to reduce reliance on imported water supplies.
Preparatory site work is already underway, setting the stage for major construction. The current timeline for the project is as follows:
Fall 2026: Advance site preparations culminate in a substantial drawdown of the lake. IRWD plans to modify the outlet tower to lower water levels as much as possible.
Summer 2027: Major structural construction on the dam begins.
2027–2030: Heavy engineering and construction span roughly four dry seasons, during which water will not be retained behind the dam.
2030: Expected project completion and facility restoration.
While shoreline fishing has continued under OC Parks management during initial prep work, full construction will end fishing activities for the foreseeable future.
Irvine Lake’s warmwater lineup includes: M1 largemouth bass, crappie, bluegill, white sturgeon, world-record class blue catfish. The lake’s deep structure and decades of limited access have allowed fish to grow to extraordinary size, especially the blue catfish, which have been quietly maturing for up to 30 years.
“White sturgeon are under statewide catch‑and‑release only regulations,” said Izorline’s Wendy Tochihara. “Under California Fish & Game Code, ‘take’ includes kill, harm, or destroy, which I think means, IRWD cannot legally allow white sturgeon to die during dewatering.”
Tochihara also suggested that since white sturgeon are present, the CDFW could possibly intervene and demand IRWD implement fish salvage, species-specific relocation, biological monitoring and other mitigation measures.
“Could this protection force agencies to save all fish in the lake, including the world‑record blue catfish and M1 largemouth and waste‑of‑game violations?” asked Tochihara. “Draining the lake without salvage would kill thousands of gamefish, creating a clear violation of §2002.”
California Fish & Game Code §2002 prohibits the waste of gamefish, including: bass, catfish, crappie, bluegill and wipers.
“We need to implore anglers, guides, and conservation advocates to push for a full fish‑salvage and relocation plan, white sturgeon verification by CDFW, mitigation and restocking commitments and protection of a public trust fishery managed through OC Parks.We need to urge the fishing community and agencies to act before the October 26, 2026 drawdown. Irvine Lake is a historic fishery with a warmwater ecosystem found nowhere else in Southern California. Dewatering without salvage would erase decades of fishery development and destroy one of the region’s most beloved angling destinations. Whether Irvine Lake’s legendary fish survive depends on what happens next and how loudly the fishing community speaks.”
Who to contact:
Fish & Game Commission: fgc@fgc.ca.gov
Santa Ana Regional Water Quality Control Board: region8info@waterboards.ca.gov
Letter Template:
My letter to the Santa Ana Regional Water Quality Control Board regarding Tentative Order R8‑2026‑0042 and the planned October 26, 2026 dewatering of Irvine Lake.
Re: Tentative Order R8‑2026‑0042 – Required Fish‑Salvage and Biological Mitigation for Irvine Lake Dewatering
Santa Ana Regional Water Quality Control Board
Attn: Dredged and Fill Material Program
3737 Main Street, Suite 500
Riverside, CA 92501
Dear Chair and Board Members,
I am submitting this formal comment regarding Tentative Order R8‑2026‑0042, which authorizes the Irvine Ranch Water District (IRWD) to proceed with the full dewatering of Irvine Lake beginning October 26, 2026 as part of the Santiago Creek Dam Improvement Project. The Tentative Order acknowledges 162.23 acres of temporary impacts and 3.22 acres of permanent impacts, including impacts caused directly by dewatering of Irvine Lake.
As written, the Tentative Order does not include any fish‑salvage, species‑protection, or fishery‑mitigation requirements. Because the planned dewatering will result in the death of all fish inhabiting Irvine Lake, including white sturgeon, trophy‑class warmwater gamefish, and blue catfish of world‑record proportions, the Order must be revised to include mandatory biological protections.
I. Unlawful Take of White Sturgeon – Fish & Game Code §2000
White sturgeon (Acipenser transmontanus) are currently under statewide catch‑and‑release only regulations. Under California Fish & Game Code §2000, it is unlawful to “take” fish except as permitted by regulation. “Take” includes kill, harm, or destroy.
Draining Irvine Lake without a fish‑salvage plan will result in the foreseeable and complete mortality of white sturgeon present in the reservoir. This constitutes an unlawful take under §2000.
The Water Board cannot authorize a project that results in unlawful take of a protected species.
II. Waste of Gamefish – Fish & Game Code §2002
Irvine Lake contains a well‑documented warmwater fishery, including:
• M1 largemouth bass
• Crappie
• Bluegill
• Wipers
• Trophy‑class blue catfish
• White sturgeon
These species are recognized gamefish under California law.
Fish & Game Code §2002 prohibits the waste of fish normally pursued for sport or recreation.
Allowing thousands of gamefish to die due to intentional dewatering is a clear violation of §2002.
The Water Board must require mitigation that prevents waste of gamefish.
III. CEQA – Significant Biological Impacts Require Mitigation
The Tentative Order acknowledges substantial environmental impacts, including:
• Dewatering of a major reservoir
• Loss of aquatic habitat
• Loss of riparian function
• Permanent impacts to waters of the state
Under CEQA, these impacts are significant and must be mitigated.
A mass fish kill is a significant biological impact requiring:
• Fish salvage
• Relocation
• Biological monitoring
• Post‑construction restocking
• Habitat restoration
The Tentative Order currently lacks these required measures.
IV. Public Trust Obligations
Irvine Lake is managed for public recreation through OC Parks.
The fishery is a public trust resource, and its destruction would violate:
• Public trust doctrine
• Recreational access commitments
• OC Parks’ stewardship obligations
The Water Board must ensure that IRWD’s project does not eliminate a public trust fishery.
V. Required Revisions to Tentative Order R8‑2026‑0042
To comply with state law, CEQA, and public trust obligations, the following revisions are required:
1. Mandatory Fish‑Salvage and Relocation Plan
IRWD must develop and implement a fish‑salvage plan that includes:
• Capture and relocation of white sturgeon
• Salvage of warmwater gamefish
• Qualified fisheries biologists
• Monitoring and reporting requirements
2. Species‑Specific Protections for White Sturgeon
The Order must require:
• Verification of sturgeon presence
• Salvage protocols
• Mortality‑avoidance measures
3. Prohibition on Dewatering Until Salvage Is Complete
The Order must state that no dewatering may occur until salvage and biological protections are implemented.
4. Compensatory Mitigation for Fishery Loss
Mitigation must include:
• Post‑construction restocking
• Habitat restoration
• Long‑term monitoring
• Success criteria
5. CEQA Biological Mitigation Compliance
The Order must incorporate CEQA mitigation measures addressing:
• Aquatic habitat loss
• Species protection
• Fishery restoration
VI. Conclusion
The planned October 26, 2026 dewatering of Irvine Lake will result in the total loss of a historic warmwater fishery, including white sturgeon and blue catfish of world‑record size, unless the Water Board requires fish‑salvage and biological mitigation.
Tentative Order R8‑2026‑0042 must be revised to include:
• Mandatory fish salvage
• Species‑specific protections
• Mitigation and monitoring
• Post‑construction fishery restoration
• Prohibition on dewatering until protections are in place
I respectfully request that the Board incorporate these requirements before adopting the Order.
Thank you for your attention to this matter.
I also sent a letter to the Fish & Game Commission a few minutes ago.
Sincerely,
XXXXXXXX YOUR NAME HERE XXXXXXXXXXX
