Committee examines H.397 language to allow pre‑flood dam drawdowns under governor’s emergency authority

The Senate Natural Resources and Energy Committee reviewed proposed language in H.397 on May 7 that would authorize pre‑flood drawdowns of reservoirs and dams under the governor’s emergency authority, subject to conditions and an approved drawdown plan.

Legislative counsel described new subdivision language that would let the governor, in consultation with the secretary of natural resources, authorize temporary waiver of permits and water‑quality restrictions to lower water levels when a flood event “is likely to cause substantial damage or injury,” but only if officials reasonably conclude the drawdown will reduce that risk. The draft requires dam operators using a waiver to adopt a secretary‑approved drawdown plan before implementation.

Why it matters: proponents say pre‑event drawdowns can reduce overtopping and downstream flood damage by using existing reservoir capacity; opponents and agency staff warned the tactic can harm dams or aquatic ecosystems if done without engineering analysis and adequate lead time.

Key details

- Waiver trigger and guardrails: Legislative counsel explained the waiver is to be used only when the governor, after consultation, finds a flood event likely to cause substantial damage and that a drawdown will reduce that risk. Ben Green, section chief at the Department of Environmental Conservation, recommended that dam owners “should be required to develop an improved drawdown plan that includes communications, drawdown rates, target flows and levels, as well as monitoring and reporting requirements.”

- Drawdown plan requirements: The bill language discussed in committee would require hydrologic and hydraulic modeling by an engineer experienced in dam safety, communications with downstream communities and regulators, maximum safe drawdown rates and target reservoir elevations, a refill plan if the target cannot be met during the event, and monitoring and reporting of drawdown operations.

- Benefits and risks: DEC staff said some dams could use pre‑event drawdowns to reduce overtopping risk, but most Vermont dams were not built for flood control. Ben Green highlighted engineering and environmental risks including erosion, outlet‑work damage and adverse impacts to reservoir and downstream ecology if drawdowns are done too quickly or without proper planning. He said meaningful drawdown generally requires multiple days’ lead time and hydrologic forecasting.

- Jurisdictional limits and FERC facilities: Counsel and agency staff noted jurisdictional complexity. Title 10, chapter 43 governs non‑hydropower, nonfederal dams; FERC‑regulated and federally owned dams follow other federal regimes. Committee members asked whether the governor could lawfully waive federal permits; counsel flagged that the provision is intended to cover a broader range of dams than chapter 43 alone and that federal permits may not be waivable by the governor.

Committee reaction and next steps

Members and agency staff urged clearer guardrails about who makes the determination that a damaging flood is imminent and recommended specifying the decision authority in the bill. DEC asked for the drawdown plan requirement to be explicit and urged that plans prove any expected flood‑risk benefit through modeling before a waiver is issued. The committee did not record a formal vote on the draft language; members suggested GovOps consider adding clarifying language about decision authority and plan requirements.

What was not decided: how language should interact with federal licensing for hydropower dams and whether the governor’s emergency waiver authority can supersede federal permits; counsel indicated the bill’s placement and drafting could be adjusted so that the provision would cover a broader set of dams and provide the necessary statutory authority.