Water resources of the Port Madison Indian Reservation, Washington

Water-Resources Investigations Report 78-112
Prepared in cooperation with Suquamish Tribal Council



The study summarized in this report was made to provide Suquamish Tribal leaders with information on the reservation's surface- and ground-water resources. The Tribal leaders need this information to help them manage and protect their water resources against overdevelopment. The quantity of ground water that is estimated to be available for withdrawal on a long-term basis is about 600 million gallons per year in the western part of the reservation and 400 million gallons per year in the eastern part of the reservation. It should be possible, economically and practically, to capture at least 40 percent of this ground water with properly constructed and located wells before it is discharged into the sea. This is enough water to supply at least 5,000 and 3,500 people with domestic water in these respective areas—about four times the present population.

Of nine stream sites that were studied on and near the reservation, the lowest average streamflows for a 7-day period estimated to occur an average of once in 2 years were 1.3 cubic feet per second or less. Streams at three of the sites have been observed dry at least once. The short period of data collection during this study limits the accuracy of statistical estimates of low flows.

Both surface and ground water were found to be of good quality with no unusual or harmful constituents; there was no evidence of major pollution in 1977. In the future, seawater intrusion into the ground-water system and pollution of the surface water by improperly treated sewage waste water could become problems.

Study Area

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Water resources of the Port Madison Indian Reservation, Washington
Series title Water-Resources Investigations Report
Series number 78-112
DOI 10.3133/wri78112
Year Published 1979
Language English
Publisher U.S. Geological Survey
Description Report: vi, 73 p.; 1 Plate: 22.45 x 21.71 inches
Country United States
State Washington
Other Geospatial Port Madison Indian Reservation
Datum National Geodetic Vertical Datum of 1929
Google Analytic Metrics Metrics page