The residents of the Makah Indian Reservation depend on the streams of the area for their fisheries and domestic water supply. The temporal distribution of streamflow in the study area is closely related to the amount and distribution of rainfall. In a year of average precipitation about three-quarters of the streamflow can be expected to occur during the 6-month period October-March. Although the chemical quality of water in streamsis suitable for domestic purposes, State water-quality standards are not met by most streams at certain times of the year because of excessive fecal-coliform bacteria and turbidity levels. Nutrient concentrations in the Waatch and Sail Rivers are sometimes high enough to cause nuisance-plant growth. Suspended-sediment concentrations were low in all streams sampled.
Ground water is known to occur only in sand and gravel layers that underlie the lowlands of the reservation. Individual wells are capable of yielding as much as 90 gallons per minute. Several wells in the Neah Bay area have been abandoned because of inferior water quality. In coastal areas, an individual domestic well on each 10-acre allotment should provide sufficient water for the occupants without danger of seawater intrusion.
