The City of Bainbridge Island’s Draft Groundwater Management Plan:   It’s not a plan for the sustainable management of Bainbridge Island’s aquifers

The City of Bainbridge Island’s groundwater management plan is emerging, not as a plan for the long-term sustainable management of Bainbridge Island’s groundwater, but rather as a plan to manage the depletion of Bainbridge Island’s aquifers to accommodate accelerated growth.

—Newsletter, September 1, 2025—

The City of Bainbridge Island’s groundwater management plan is emerging, not as a plan for the long-term sustainable management of Bainbridge Island’s groundwater, but rather as a plan to manage the depletion of Bainbridge Island’s aquifers to accommodate accelerated growth.

There are three fatal flaws in the City’s draft groundwater management plan:

1. It prioritizes growth over the sustainable management of groundwater;
2. It contains a skewed interpretation of the Growth Management Act focused on housing while completely ignoring GMA protections for groundwater;
3. It fails to recognize the important role land use zoning and regulations play in sustainable groundwater management.

When you hear the words groundwater management plan you might assume it’s a plan for the long-term sustainable management of groundwater. After all, isn’t that the purpose of a groundwater management plan? The City’s draft GWMP, however, is primarily about managing the depletion of Bainbridge Island’s freshwater aquifers so that massive up zoning and growth can proceed unimpeded. It does that, in part, by leaning heavily on supposed growth mandates from the State.

So what are the solutions for fixing the City’s deeply flawed GWMP?

It’s going to require a significant amount of public pressure to budge the City off its current position of prioritizing growth over the sustainable management of Bainbridge Island’s groundwater.Here’s a summary of what would make a good groundwater management plan for Bainbridge Island:

1. Change the draft GWMP to become a genuine plan for the long-term sustainable management of Bainbridge Island’s groundwater consistent with long-standing comprehensive plan goals and policies. It needs to call for serious actions, including land use controls, to prevent declines in the Island’s aquifers.
2. The City’s disinformation campaign regarding the requirements of the Growth Management Act needs to stop. Bainbridge Island is the only EPA certified Sole Source Aquifer island-city surrounded by saltwater in the entire United States. Protection of Bainbridge Island’s groundwater resources is not preempted by GMA housing requirements. Claiming otherwise is dishonest and poses a dire threat to the future of Bainbridge Island, our quality of life, and the health of the Island’s natural environment.
3. The City needs to delay any plans for up-zoning parts of the Island until increased pumping can be evaluated for consistency with the LONG-TERM sustainable management of Bainbridge Island’s groundwater resources.
4. The GWMP needs to explicitly provide for potential future land use restrictions to mitigate groundwater drawdowns. Potential future restrictions need to consider impacts of pumping from aquifers, loss of recharge due to development activities, and potential pollution of groundwater. Land owners and developers need to know that future development is contingent upon sustainable groundwater management and not the other way around.
5. A balanced representation of GMA requirements need to run through the final GWMP, highlighting the GMA’s requirement to protect groundwater and with fewer references to HB 1220 and no statements saying or implying that growth requirements preempt the City’s obligation to promote the long-term sustainable management of Bainbridge Island’s groundwater resources.
6. The GWMP needs to include consideration of tribal treaty rights, mainly potential impacts to stream levels that marine species migrating to and from Bainbridge Island’s streams depend on.
7. The GWMP needs to include a more realistic description of mitigation measures, including conservation, without exaggerating their benefits.

The City of Bainbridge Island’s Long-standing Commitment to Sustainability

From the Guiding Principles and Policies found in the Introduction to Bainbridge Island’s comprehensive plan:

Guiding Policy 2.1
Manage water resources for Bainbridge Island for present and future generations, recognizing that the Island’s finite groundwater resources [aquifers] are the sole source of our water supply.

Guiding Policy 2.2
As part of long-range land use planning, consider the impacts of future development to the quality and quantity of groundwater that will be available to future Islanders and to the natural environment. To that end, strive for sustainable groundwater withdrawal, conserve aquifer recharge, guard against seawater intrusion and prevent adverse impacts to ground water quality from surface pollution.

Guiding Policy 2.3
Preserve and protect the ecologicalfunctions and values of the Island’s aquatic resources.

Guiding Policy 2.5
Create a Bainbridge Island groundwater management plan for the purpose of maintaining the long-term health of our fresh water aquifers.

Guiding Policy 2.6
Recognizing the importance of our ground water and other water resources to present and future generations of Bainbridge Islanders, apply the precautionary principle.

Guiding Principle #5
The use of land on the Island should be based on the principle that the Island’s environmental resources are finite and must be maintained at a sustainable level.

Guiding Policy 5.1
Regulate all development on the Island consistent with the long-term health and carrying capacity of its natural systems.

Guiding Policy 5.3
Preserve and enhance the Island’s natural systems, natural beauty and environmental quality.

Guiding Policy 5.4
Protect and enhance wildlife, fish resources and natural ecosystems on Bainbridge Island.

Guiding Principle #6
Nurture Bainbridge Island as a sustainable community by meeting the needs of the present without compromising the ability of future generations to meet their own needs.

Here’s what the comp plan’s Land Use Element has to say about respecting the Island’s carrying capacity:

GOAL LU-2

This Comprehensive Plan recognizes and affirms that as an Island, the city has natural constraints based on the carrying capacity of its natural systems. The plan establishes a development pattern that is consistent with the Goals of the community and compatible with the Island’s natural systems.

Policy LU 2.1

Recognizing that the carrying capacity of the Island is not known, the citizens of Bainbridge Island should strive to conserve and protect its natural systems within the parameters of existing data.Revisions to the Plan should be made as new information becomes available.

The carrying capacity of Bainbridge Island is determined by many factors including the supply of limited resources (particularly water), changes in patterns of consumption and technological advances. This Plan acknowledges that with current information, the carrying capacity of the Island is unknown. During the timeframe of this Plan, additional information on the carrying capacity of the Island should be developed.

The plan takes a balanced and responsible approach to future development. As our understanding of the Island’s capacity changes, the recommendations of this Plan should be reconsidered to ensure they continue to represent a responsible path for the long-range future of the Island.

The City of Bainbridge Island’s switcheroo

So why is our city government straying so far from its long-held commitments to sustainability, to the point of prioritizing growth over sustainable management of Bainbridge Island’s groundwater?

The issue of groundwater on Bainbridge Island has long been a point of contention between those who want to promote the long-term sustainable use of groundwater for both people and the natural environment verses those who are more interested in the money to be made from growth and development on Bainbridge Island. The latter unfortunately includes the City of Bainbridge Island with its desire for ever-increasing revenues. Add to this the natural desire by more and more people to call Bainbridge Island home. Not only have the comp plan’s lofty ideals about sustainability not been universally embraced, long-standing policies of preserving Bainbridge Island’s special character and promoting the sustainable use of its finite natural resources are now being described by some as exclusionary.

The tipping point between sustainability and growth came mainly because of two things:

1) Appendix F—Housing Allocation Through 2044— of Kitsap County’s countywide planning policies and;

2) House Bill 1220 (HB 1220), signed by Governor Inslee in 2021.

The stated purpose for Appendix F’s housing allocation is:

… for jurisdictions to provide capacity for housing and to remove barriers to developing housing.

Here are Appendix F housing allocations for Bainbridge Island:

• • Total allocation for 2020-2044: 1,977 new housing units;
  • Permanent supportive housing: 166 units;
  • >30-50% adjusted median income (AMI): 324 units
  • >50-80% AMI: 272 units;
  • >80-100% AMI: 140 units;
  • >100-120% AMI: 138 units;
  • >120% AMI: 560 units;

  Appendix F is reinforced by HB 1220, which is implemented by RCW 36.70A.070(2) of the Growth Management Act. HB 1220 language from the GMA includes:

  (2) A housing element ensuring the vitality and character of established residential neighborhoods that:

  (c) Identifies sufficient capacity of land for housing including, but not limited to, government-assisted housing, housing for moderate, low, very low, and extremely low-income households, manufactured housing, multifamily housing, group homes, foster care facilities, emergency housing, emergency shelters, permanent supportive housing, and within an urban growth area boundary, consideration of duplexes, triplexes, and townhomes;

  An underlying assumption of both Appendix F and HB 1220 is that barriers to housing, be it resistance to up-zoning or the desire to retain the special character of a community, are exclusionary. City of Bainbridge Island officials have, for example, described single-family zoning on the Island as racist. This view has even been used as a litmus test for applicants to the City’s planning commission. Recently, the phrase, “Winslow’s small-town atmosphere and function”—long-standing language from the Guiding Principles of Bainbridge Island’s comprehensive plan—has been described as exclusionary and flagged for removal. We’re told the same equity lens will be used to flag other supposedly offensive language in Bainbridge Island’s comprehensive plan. Will this include phrases like “carrying capacity” and “sustainability”?

  The problem with using Appendix F and HB 1220 as a holy grail for groundwater management and future development on Bainbridge Island is that they represent only one set of requirements from the Growth Management Act. Part of the GMA’s emphasis on protecting the natural environment, here’s what it says about protecting groundwater resources.

  RCW 36.70A.070
  Comprehensive Plans—Mandatory Elements
  Each comprehensive plan shall include a plan, scheme, or design for each of the following:

  1. A land use element … The land use element shall provide for protection of the quality and quantity of groundwater used for public water supplies.

  Nothing in the GMA prioritizes housing over the protection of groundwater resources. In the City’s draft groundwater management plan (GWMP), however, the City mentions HB 1220 housing requirements eleven times. It doesn’t mention the GMA’s requirement for the protection of groundwater even once. That seems a bit odd considering it’s a groundwater management plan. The draft GWMP also fails to mention any of the City’s long-standing commitments to the sustainable use of the Island’s groundwater and other natural resources contained in Bainbridge Island’s comprehensive plan.

  This bias isn’t new. It’s always been there. Now it’s being given encouragement and cover by HB 1220 and other extreme legislation coming out of Olympia.

  Affordable housing is expensive and challenging to produce.

  Zoning for and creating affordable housing is extremely difficult, especially in highly desirable places like Bainbridge Island. The City’s Planning Commission, which has been grappling with this issue for the last few months, has come to that realization. The only way to ensure the creation of affordable housing is through inclusionary zoning, which results in no more than 10% affordable along with 90% market rate housing units in a housing project, and expensive subsidies and programs. With limited public funds, meeting the supposed housing mandates of HB 1220 and Appendix F can only happen with massive up-zoning for inclusionary zoning—lots of market rate housing for a small amount of affordable housing. That’s what the City is pushing for through updates to the Winslow Subarea Plan and the Bainbridge Island Comprehensive Plan.

  Adding to this challenge is the fact that the City’s groundwater modeling shows significant declines in Bainbridge Island’s aquifers associated with continued growth. To resolve this conundrum the City has decided to disregard its goals related to the sustainable use of the Island’s finite groundwater resources. Projected declines in Bainbridge Island’s aquifers are now described at the City as a “sustainable outcome” and “manageable”.

  The Science

  While there is some disagreement among scientists, especially around future impacts to recharge and projected rainfall, the science provided in the draft groundwater management plan clearly predicts serious drawdowns of important aquifers, mainly in the deep Fletcher Bay Aquifer. The following is from the City’s July 2025 draft of Bainbridge Island’s groundwater management plan (GWMP).

  Page 2-46: Table 2-5. Findings 2011 USGS Groundwater Model
  A 2008 simulation found the following for pre-development to 2008:

  A “General decline in water level altitudes in deeper aquifers (0-10 feet in Sea Level Aquifer and 10-35 feet in the FBA (Fletcher Bay Aquifer)”.

  P. 2-49: Table 2-7. Key Findings 2015 Bainbridge Island Groundwater Model

  A simulation of the Island’s groundwater system found the following regarding how long it takes for rainwater to percolate down through the earth to aquifers. The information cited below fails to acknowledge that recharge from groundwater coming from off-island was determined by the USGS in 2009 to comprise only about 5% of Bainbridge Islands groundwater:

  Wells in deep aquifers (including the Glacio-Marine Aquifer and the FBA) may withdraw water that originates as recharge relatively distant from the wellhead and is greater than 100 years old.

  Not all groundwater on Bainbridge Island comes from recharge on Bainbridge Island. Model results indicate several wells tapping the deeper aquifers withdraw water that originates as recharge from areas on the Kitsap Peninsula and is greater than 1,000 years old.“

  Page ES-7: From the Mid Impact Planning Scenario Summary Table

  Sea Level Aquifer (SLA)

  Groundwater levels are simulated to decrease by 6 feet after 100 years. This is primarily located around the South Bainbridge Well field, suggesting the increase in mean sea level offsets effects of decreased recharge and increased pumping in the SLA.

  Glaciomarine Aquifer (GMA)

  Groundwater levels are simulated to decrease by 46 feet after 100 years. This is primarily centered around Island Utility Well field, due to FBA wells creating drawdown in the aquitard separating GMA and FBA. The portion of the aquifer with groundwater elevations below mean sea level expands past the footprint of the island faster and to a greater overall extent than the Low Impact simulation results.

  Fletcher Bay Aquifer (FBA—deepest aquifer)

  Groundwater levels are simulated to decrease by 71 feet after 100 years. 80-100 feet of drawdown are simulated within approximately a 2,000-foot radius around Island Utility Wells 1 and 3 and approximately a 1,000-foot radius around Sands Road wells 1 and 2. The northern part of the island experiences less drawdown, 60 to 80 feet and 40 to 60 feet, due to being less proximate to the Island Utility, Sands Road, and Fletcher Bay wells.

  These modeling results clearly indicate that continued growth, and especially accelerated growth, is not compatible with the long-term sustainable management of Bainbridge Island’s groundwater resources. Long-term mining of Bainbridge Island’s aquifers do not bode well for the future. It includes an increased potential for saltwater intrusion, declining well levels, failed new wells, water-starved streams and wetlands, and potentially expensive water from our neighbors to the West after we overshoot the capacity of Bainbridge Island’s freshwater aquifers. It won’t happen right away but this is the path our city want to put us on in its quest to push for accelerated growth.

  Mitigation

  As illustrated by Vashon Island’s groundwater management plan, land use controls are the primary way to mitigate projected declines in groundwater levels. Vashon’s GWMP was approved in 1998 by King County. It’s been successfully used to inform land use densities, limit groundwater pumping, reducing the potential for saltwater intrusion, and to promote aquifer recharge. Vashon is not an island-city but it is an EPA designated Sole Source Aquifer Island similar to Bainbridge Island. Both islands are designated as critical aquifer recharge areas (CARA), a critical area as defined by Washington’s Growth Management Act.

  Land use restrictions not included as mitigation in Bainbridge Island’s Plan.

  Bainbridge Island’s draft GWMP preempts the important connection between the health of the Island’s aquifers and land use zoning by citing state growth requirements and accepting them as mandates. This is a biased interpretation of the Growth Management Act and potentially turns Bainbridge Island’s GWMP into a groundwater mining plan that protects growth as opposed to the long-term health of Bainbridge Island’s groundwater resources. At the very least, Bainbridge Island’s GWMP must explicitly provide for potential future development restrictions, including down-zoning and development moratoriums, to mitigate continued drawdowns in Bainbridge Island’s aquifers.  Identifying these actions as possible future mitigation in Bainbridge Island’s GWMP would weaken and discourage challenges by development interests over zoning changes and restrictions needed to sustainably manage Bainbridge Island’s groundwater resources.

  How do you mitigate something that’s already happened?

  Once properties have been up-zoned, with no explicit provisions for potential down-zoning, it’s highly unlikely those additional developments rights would ever be taken away. That seems to be part of the City’s strategy: Pave the way for up-zoning, with biased interpretations of the GMA and overstated promises to mitigate drawdowns of the Island’s aquifers. Once up zoning is done it will become the new normal, extremely difficult to undo. This attitude, and the City’s desire for major up-zoning, is at the heart of the City’s overall approach to groundwater management.

  The draft GWMP relies on relatively weak mitigations:

  Monitoring water levels in streams: Table ES-2 outlines a process for monitoring stream levels and potentially limiting nearby pumping based upon state” in-stream flow rules” and critical areas regulations. This would likely have no impact on the City’s plans for massive up-zoning and expansion of Winslow.

  Early Warning Levels (EWL): EWL sets arbitrary limits for increased levels of chloride and maximum 0.5 foot/year declines in water of monitored wells. No scientific basis has been provided to support the assumption that anything less than a 0.5 foot decline per year decline in water levels equals a “safe yield”.

  Exceeding EWL requires additional sampling and field investigation. The draft GWMP calls for adjusting EWL standards relative to the thickness of aquifers and how well levels recover after being rested following the triggering of EWL. Absent precautionary policies related to growth and zoning densities, the probability of saltwater intrusion and over-pumping of aquifers will essentially be baked into Bainbridge Island’s land use zoning. In that scenario, the ability of EWL to protect groundwater is questionable.

  Water Conservation: Besides land use restrictions, water pricing is the primary tool available for the City to reduce water consumption. Other conservation measures cited in the draft GWMP include: public education; lower water pressures; leak detection and repair; responsible landscaping and irrigating; alternative water sources, such as rainwater harvesting; and water use restrictions. No estimates are provided for the extent to which these mitigation measures would offset increased groundwater pumping and reductions in recharge associated with the City’s current plans to massively up-zone Winslow and possibly other parts of Bainbridge Island.

  Water reuse: The City recently hired a consultant to develop plans for reusing treated sewage to recharge aquifers. The resulting scenarios were expensive and the benefits appeared minimal in comparison. Like much the City’s discussions about water conservation, the whole exercise appeared more performative than serious.

  Drilling new wells: One mitigation strategy to address declining aquifers identified in the City’s draft GWMP is to drill more wells around the island. The theory is that by distributing drawdowns over a wider area there will be less impact to aquifers. This is an expensive and unproven mitigation measure.

  So what are the solutions for fixing the City’s deeply flawed GWMP?

  It’s going to require a significant amount of public pressure to budge the City off its current position of prioritizing growth over the sustainable management of Bainbridge Island’s groundwater. Here’s a summary of changes needed to make a good groundwater management plan for Bainbridge Island:

  1. Change the draft GWMP to become a genuine plan for the long-term sustainable management of Bainbridge Island’s groundwater resources consistent with long-standing 2016 comprehensive plan goals and policies.
  2. It needs to call for serious actions, including land use controls, to prevent declines in the Island’s aquifers;
  3. The City’s disinformation campaign regarding the requirements of the Growth Management Act needs to stop. Bainbridge Island is the only EPA certified Sole Source Aquifer island-city surrounded by saltwater in the entire United States. Protection of Bainbridge Island’s groundwater resources is not preempted by GMA housing requirements. Claiming otherwise is dishonest and poses a dire threat to the future of Bainbridge Island, our quality of life, and the health of the Island’s natural environment;
  4. The City needs to delay any plans for up-zoning parts of the Island until increased pumping can be evaluated for consistency with the LONG-TERM sustainable management of Bainbridge Island’s groundwater resources;
  5. The GWMP needs to explicitly provide for potential future land use restrictions to mitigate groundwater drawdowns. Potential future restrictions need to consider impacts of pumping from aquifers, loss of recharge due to development activities, and potential pollution of groundwater. Land owners and developers need to know that future development is contingent upon sustainable groundwater management and not the other way around;
  6. A balanced representation of GMA requirements need to run through the final GWMP, highlighting the GMA’s requirement to protect groundwater (see earlier citation) and with fewer references to HB 1220 and no statements saying or implying that growth requirements preempt the City’s obligation to promote the long-term sustainable management of Bainbridge Island’s groundwater resources;
  7. The GWMP needs to include consideration of tribal treaty rights, including adverse impacts to Bainbridge Island’s streams, which marine species migrate to and from;
  8. The plan needs to include a more realistic description of mitigation measures, including conservation, without the City’s typical exaggeration of their benefits.

  Another reason a good groundwater management plan for Bainbridge Island is so important—Comp Plan certification by the State

  A good groundwater management plan will set the tone for future City actions. It will also inform Bainbridge Island’s updated comprehensive plan and serve as a backstop against the state’s aggressive housing requirements. When Bainbridge Island’s comprehensive plan goes to Puget Sound Regional Council’s Growth Management Policy Board for consideration, there will need to be a rationale for limiting growth on the Island. That rationale mainly needs to come via a good groundwater management plan that prioritizes long-term sustainable management of our groundwater resources for both future generations of Bainbridge Islanders and the natural environment.

  Now is a good time to comment on the current draft GWMP

  The City would like us to wait and comment after the final groundwater management plan is developed and released but they will accept comments now. You can send your comments to: pwadmin@bainbridgewa.gov

  To obtain a copy of the 2^nd draft of Bainbridge Island’s Groundwater Management Plan use this link (https://cityofbainbridgeisland.civilspace.io/en/projects/groundwater-management-plan)

  Development of the City’s groundwater management plan for Bainbridge Island will continue into the Fall with a public meeting date yet to be determined. BCC will provide more information as the process moves forward. Please remember that your attention to what the City is doing on our behalf will not only affect our quality of life, it will also affect future generations and the Island’s natural environment for many years to come.