Sitka sustainability coordinator outlines 100‑year hydro history and options for meeting rising electricity demand

Bree Gable, Sitka’s sustainability coordinator, walked webinar attendees through the city’s roughly 100‑year hydroelectric history, the current arrangement of two municipal dams and local substations, and a set of choices Sitka faces as electricity demand edges up.

Gable said Sitka’s Blue Lake and Green Lake hydro projects together typically operate in the roughly 10–20 megawatt range and that the town remains largely self‑contained: generation at the lakes is transmitted to Jarvis Street and Marine substations and distributed across the community. “We are completely reliant on those two hydroelectric projects here in Sitka,” she said, adding that islanded systems cannot lean on regional neighbors for balancing or emergency support.

The presenter described long project timelines and stakeholder roles in hydro development, including utilities, engineers, investors and the Federal Energy Regulatory Commission (FERC), which issues licenses and can require additional environmental study. She highlighted Sitka’s 2015 Blue Lake expansion as the most recent major upgrade, saying it raised the dam and added turbines and diesel backup capacity; Gable stated the expansion increased annual generation capacity by about 30 percent.

Gable gave several recent output figures in the webinar: she said Sitka generated about “123 gigawatt‑hours” in 2023 and that roughly two‑thirds of annual energy comes from Blue Lake and one‑third from Green Lake, with diesel contributing under 1 percent as maintained backup. She also described Sitka as, in her words, effectively “99.9995% renewable” in its electricity mix. She cautioned that Sitka’s generation is rainfall‑dependent and therefore variable: “that number is not consistent,” she said, noting that sustained year‑over‑year load growth could push the system toward low‑water risk in coming decades.

Gable framed recent demand trends around community electrification: residential customers use about 38 percent of annual electricity, and local fish‑processing industry creates seasonal demand peaks. Since the Blue Lake expansion, she said year‑over‑year load growth has fallen between about 0 and 4 percent; using an illustrative 2–2.5 percent growth rate, she showed how cumulative growth could erode supply margins if no additional measures are taken.

She laid out three broad pathways: do nothing (which could increase diesel reliance as an emergency option in later decades), reactively add renewables without precise sizing, or proactively determine needs and couple targeted new generation with efficiency and demand management to reduce the scale of new infrastructure. “If we take the time to know what our options are, we can say, what is the best thing based on what we need and what we want,” she said.

Gable urged public involvement in the Sitka Community Renewable Energy Strategy (SCREST), a public process of workshops, webinars and other outreach meant to produce a shared vision and roadmap for the community’s energy future. She encouraged attendees to visit the city website listed in the webinar, sign up for email updates at sustainability@cityofSitka.com, and attend upcoming workshops in winter 2025.

The webinar closed with Gable inviting continued conversation and collaboration as Sitka shapes how it will balance hydropower, backup generation and potential new renewables in the decades ahead.