A Water Quality Baseline Inventory of Fort Clatsop National Memorial was initiated in September of 1995. Sites included in this inventory included the Lewis and Clark River, 2 permanent streams, 1 ephemeral stream, 2 ephemeral springs, 3 ephemeral ponds and 1 slough. All sites were sampled 3 times per month throughout the year, in the case of the ephemeral sites until they dried up in the summer and beginning again in the fall when the water returned.
Water quality samples included readings and measurements for temperature, conductivity, salinity, turbidity, pH, alkalinity and dissolved oxygen. Stream flow measurements were taken in the streams and springs. Nutrient and ion analyses were performed by an outside contractor 3 times during the inventory.
In November of 1998 the Baseline Inventory was ended and the Long Term Monitoring Inventory was begun. The sites chosen for long term monitoring were based on results of the Baseline Survey. Sites included the Lewis and Clark River, 2 permanent streams, 2 ephemeral ponds and 1 ephemeral spring. A sampling schedule has been set up for each individual site and is based on seasonality and results of the Baseline Survey. This monitoring program is ongoing at the present time.