Guemes Island Planning Advisory Committee:

Your Guemes AQUIFER

The Guemes Island Planning Advisory Committee (GIPAC) is a permanent, nonprofit organization of community-elected volunteers that is designated by Skagit County to represent islanders’ interests in implementation of the county’s adopted Guemes Island Subarea Plan. 

Per the Plan, GIPAC's purpose is to promote responsible growth management on Guemes Island, while at the same time working to preserve the quality of life and fragile environment of the island, including the island’s freshwater aquifers, rural character, resource lands, shorelines,critical areas, and other environmentally sensitive areas. Water on Guemes. 

Virtually all islanders are dependent on groundwater for their potable watersupply.  Islanders’ concerns about their groundwater resources are not new: the island has long suffered from water quantity and quality issues.  The Washington Department of Ecology (DoE) identified coastal seawater intrusion areas on Guemes Island in the late 1980s.

Chloride levels in wells—a bellwether of seawater intrusion—have been elevated on West Shore, North Beach, and other areas for over two decades. In the mid-1990s, as a result of islanders' research, Guemes Island was designated a “Sole Source Aquifer” by the federal government, the only one in Skagit County. About that same time, DoE raised a red flag. 

In a May 1994 letter to the Skagit County Health Department, DoE expressed strong concerns about the impact of new wells on quality and quantity of water on Guemes and recommended limiting new well construction on the north end of the island.  DoE also recommended that Skagit County discourage the drilling of new wells near the coast island-wide. When the DoE letter was written 27 years ago, there were an estimated 120 wells on Guemes.  The county has placed no controls on the drilling of new wells since then, and in 2018, the US Geological Survey reported that an additional 250 wells had been drilled since 1995.  A number of existing wells have been affected—some going dry, others being contaminated with seawaterand thus becoming unusable.

We have documentation that 64 residences on the island have suffered consequences of well failure, but that number is probably low because the county has never tracked failed wells on Guemes,Wells have failed due to seawater intrusion on North Beach, and 19 residences on West Shore had to build a very expensive reverse osmosis system, now operated by Skagit PUD, due to seawater contamination of their wells.Since 2015, GIPAC has been petitioning the County to approve rainwater catchment on Guemes as an alternative to drilling more wells. 

Despite the fact that catchment for potable water as been approved in San Juan County for two decades and works smoothly there, progress on this front in Skagit County has been painfully slow.  In 2020, the County took tentative steps to begin developing an approval framework that we hope will make catchment anwelcome and viable alternative to drilling more wells into our fragile aquifers.  

Your Guemes Aquifer Flyer


• Don’t let water run if cooking, doing dishes, washing hands or brushing teeth.

• Run dishwashers and washing machines fully loaded.

• Take shorter showers…turn water off while lathering up.

• Minimize toilet flushes.

• Reuse a pan of water by the door to wash sandy feet.

• Save washing of cars, boats and large dogs for a trip to town!

Guemes Island Planning Advisory Committee


Your Guemes AQUIFER

Our island, like most others, has a very limited water supply and we need your help to sustain it. We rely on underground aquifers for our water, which are only recharged by rainfall.

Most rainfall never makes its way into the aquifers, as it is taken up by plants or runs to the sea. We need to be water wise to protect our groundwater and prevent wells from drying ­up or failing due to seawater intrusion.

Seawater Intrusion

Beneath coastal land, fresh water “floats” on seawater. Pumping from wells causes the fresh/salt boundary to rise.

Seawater intrusion renders the water not potable. Permanently pumping down the aquifer one foot causes the seawater boundary to rise 40 feet.

Sole Source Aquifer

We have no rivers or lakes on Guemes Island and our only source of water is ground water.

In 1997 the Environmental Protection Agency (EPA) designated Guemes Island as a Sole Source Aquifer.


Guemes Island is in a rain shadow and gets an average of 29 inches of rainfall each year.

Seattle gets about 36 inches on average. Some years see belowaverage rainfall. Low rainfall means trees and plants are drier and at risk of disease and fire. Wells in different areas of the island have gone dry at times because of overuse and dry weather.

When building or remodeling:

• Use water saving plumbing fixtures, dishwashers and washing machines

• Avoid the use of garbage disposals, as they use a great deal of water. Try composting your vegetable scraps or toss them in the garbage

At the well:

• install a meter

• take monthly readings to determine usage and detect leaks

• restrict well pumping rate to minimize the risk of seawater intrusion

We can help protect our water supply.

In the garden:

Landscape with native and drought resistant plants.

Collect and use rainwater for outdoor needs.

Reduce evaporation:

• mulch

• water early or late in the day

• use a soaker hose or drip irrigation

• if you set a sprinkler, set a timer.