City updates council on Edwards Aquifer Habitat Conservation Plan renewal and continued river restoration work

City staff briefed the San Marcos City Council Tuesday on ongoing implementation of the Edwards Aquifer Habitat Conservation Plan (EAHCP), the regional program that funds habitat protection, river restoration and spring‑flow protections for endangered species in the San Marcos and Comal spring systems.

Mark Enders, Habitat Conservation Plan manager, told council the current incidental‑take permit term runs from 2013 to 2028 and that stakeholders are preparing a renewal to cover the 2028–2058 period. Enders said the HCP funds both spring‑flow protection measures (including staged reductions by the Edwards Aquifer Authority, voluntary irrigation suspension agreements and potential use of San Antonio Water System storage/recovery measures) and habitat‑protection work in the San Marcos River such as aquatic vegetation restoration, non‑native species removal, riparian restoration, litter removal and stabilized river access points.

Enders said the plan establishes flow objectives intended to support federally listed species — for example, minimum spring flows used in the program modeling include 45 cubic feet per second (cfs) for the San Marcos Springs and 30 cfs for the Comal Springs — and that the program models and implements conservation measures to achieve those objectives during drought. He described the staging program (EAA stage reductions up to 44% during severe drought) and a voluntary irrigation‑suspension program that pays irrigators to forbear use during drought years; staff noted the EAHCP and funding derive from aquifer management fees paid by Edwards Aquifer permit holders.

Enders reviewed habitat measures implemented under the HCP since 2013. That work includes aquatic vegetation and Texas wild‑rice restoration, removal of non‑native fish (including tilapia and plecostomus), riparian restoration and fencing, underwater litter collection (staff reported 1,350 cubic feet removed during 2022–2024), and a conservation crew that educates river users and helps enforce protective measures. He said the City of San Marcos has expended close to $10 million on restoration measures since 2013 and expects to expend roughly $12 million on habitat protection by the end of the current permit term; Enders said the total regional program spending across permittees has been substantially larger.

Enders also described the program’s science and monitoring framework: periodic aquatic vegetation mapping, species surveys, water‑quality monitoring and captive populations maintained for restocking if needed (programs at the San Marcos Aquatic Research Facility and U.S. Fish and Wildlife Service hatchery facilities). The HCP is governed by an implementing committee of permittees, a stakeholder committee and a science committee; the program’s work plan and annual report are reviewed by those groups and submitted to U.S. Fish and Wildlife Service.

On permit renewal, Enders said workgroups led by the Edwards Aquifer Authority are reviewing the existing HCP and drafting a proposed HCP for a 30‑year permit term. Staff expect to submit a draft HCP to U.S. Fish and Wildlife Service in 2026 and aim for a final HCP in late 2027. Enders said the renewal will seek similar coverage as the current plan (river recreation, aquifer use and restoration activities) and would add coverage for certain construction activities within or adjacent to the river to streamline project permitting. He said proposed long‑term flow objectives include retaining a 45‑cfs minimum at San Marcos Springs and seeking higher rolling averages (for example, a three‑year rolling average target) to account for climate change effects.

Enders noted a near‑term council item on the April 15 agenda: consideration of an amended interlocal agreement with Texas State University (Meadows Center) to continue aquatic vegetation restoration work; Enders said the amendment would increase compensation to the Meadows Center and that the increased work would be funded through HCP program dollars. He said the next formal council action on the HCP renewal is anticipated in mid‑2025, when council will be asked to review and support submission of a draft HCP to U.S. Fish and Wildlife Service.

Councilmembers asked detailed questions about program mechanics. Councilmember Rodriguez asked how the irrigation‑suspension payments work; Enders explained the program is voluntary, negotiated by the Edwards Aquifer Authority with irrigators, and offers a standby payment plus a larger payment when a trigger is reached and irrigators forbear use for the year. Councilmembers also asked about fencing, wildlife access and whether fences were intended to remain permanent; Enders said many fences were installed to protect restored riparian vegetation and to focus recreation at stabilized access points but acknowledged many fences include small gaps to allow wildlife movement.

Enders concluded that the proposed renewal relies on a mix of measures similar to the current program — staged reductions, voluntary agreements, storage/recovery measures and habitat restoration — and that staff will participate in reviewing and refining the draft HCP before it is submitted to federal reviewers.