Water-use conflicts occur when available water supply is insufficient to maintain minimum base flows and fulfill existing water rights and claims at the same time. Conflicts also arise when proposed uses may impair minimum base flows or existing water rights. In order to make wise management decisions about water use, the following factors must be considered Competing water uses Low flows in summer months Increasing water use Anticipated future growth Decline in fish stocks Maintenance of minimum base flows Degradation of water quality and aquatic habitat. Balancing these needs is complex. Low summer flows are caused not only by low rainfall, but-also by permitted uses for household, farming, and industrial needs.
Wells drawing water from aquifers can reduce ground-water discharge to rivers and streams.
Reduced water quality can severely damage habitat. Low stream flow can block fish migration. In the Upper Chehalis watershed the combined allocation for surface water and ground water rights and claims totals 1,202 cfs per year. Applications are on file with Ecology for an additional 46 cfs. In winter when flows are high, additional water is available for allocation.