An embattled piece of long-term city planning just took a major step forward — but it may not be the one you’re thinking of.

The Bainbridge Island City Council launched an official draft of its 100-year Groundwater Management Plan for peer review by consulting firm Keta at its July 22 meeting, a step that will provide edits and rubber-stamp the plan before opening the floor for input through public engagement in October.

“The peer review is a key component of this whole process. The groundwater plan’s before us, a draft is there, and this is the opportunity to have the experts say, ‘Is this working? Is it correct? Are we hitting the targets? Is the analysis right?” Councilmember Clarence Moriwaki said.

BI relies on underground aquifers to source its drinking and potable water, which are fed by freshwater from streams, snow and rain seeping deep into the earth. The GWMP is the city’s attempt to plan for the availability of water for humans and the environment alike, given population growth and the effects of climate change.

The GWMP functions alongside the Comprehensive Plan, another long-term city planning document that will steer BI’s development and resource use, but it has attracted about a third of the amount of public engagement that the Comp Plan has received, and will govern for about five times as long, up to 100 years.

The draft lays out three potential scenarios — low, middle and high impact — that could shape how BI’s aquifers change over the next 100 years.

In 20-50 years, in the best case or low-impact scenario, the city could see south end production water wells drop below sea level by 2050, and two of its deep aquifers lose 16-23 feet, affecting about 53% of wells on the island. Middle-tier impacts project that all three of BI’s deep aquifers could drop below sea level — in some cases extending beyond the footprint of the island, and one in Fletcher Bay could drop by 60 feet.

Some residents, including hydrogeologists and City Council candidates, expressed concern that the timeline of the council’s two long-term planning documents is not aligned, and that the draft GWMP still contains concerning oversights.

Benjamin Harrison, a member of the city’s Environmental Technical Advisory Committee, a group of scientists and engineers who analyze environmental concerns for the city, said that the draft of the GWMP does not look realistically at potential outcomes that BI may face in the next several decades.

“The second draft continues to present an overly optimistic perspective on the impact of climate change on aquifer recharge. Combined land use changes, alteration to the intensity and seasonality of rainfall and temperature make significant decrease to recharge the most likely scenario, whereas the draft presents limited change as the most likely,” Harrison said. “This concern should … encourage the council to act on management on an accelerated schedule.”

Harrison pointed out that the public engagement period of the GWMP will take place in October, before council approves the document in November. He called on the city to perform more public engagement.

Mike Nelson, a South Ward resident who is running for council, called on councilmembers to “finalize the groundwater management plan and have it peer reviewed before making changes to our zoning and finalizing the comprehensive plan.

“This is just common sense. BI is designated as a sole-source aquifer and gets all of its drinking water from groundwater. The draft of the GWMP raises serious concerns about the long-term sustainability of our water supply due to measurable annual declines in our groundwater aquifers,” Nelson said. “Prudence and responsible growth planning demand that we look closer at this issue to determine the seriousness of it before finalizing our plans for future growth.”