Skip to main content

Thurston County, Washington

The content on the Thurston County website is currently provided in English. We are providing the “Translation” for approximately 10 languages. The goal of the translation is to provide visitors with limited English proficiency to access information on the website in other languages. The translations do not translate all types of documents, and it may not give you an exact translation all the time. The translations are made through an automated process, which may not result in accurate or precise translations, particularly of technical and legal terminology.

Community Planning and Economic Development

Detailed Environmental Monitoring data for engineers, modelers and researchers.

​Water Year: A 12-month period that runs from October - September.  For example, Water Year 2017 runs from October 1, 2016--September 30, 2017.  Hydrologists use this modified calendar to more accurately reflect what's happening with seasonal rainfall, flooding and drought.

Thurston County used five control wells in the Salmon Creek Basin to establish a standard measure for groundwater levels.  They are still being monitored. See their location on this map (PDF) and check groundwater levels on the dashboard

Baseline measures were taken from data collected in 1999 and again in 2010.

  1. Well LRS-01A at SW Foster.
  2. Well LRS-06 (now out of commission).
  3. Well LRS7a  at  SW 93rd.
  4. Well LRS8 at SW Walter Court.
  5. Well LRS11a at S. Tilley Rd.

All elevation data is in NGVD'29. There is currently an effort under way to convert all elevations to NAD '88.

NGVD'29 was the vertical control datum established for vertical control surveying in the United States of America by the General Adjustment of 1929. The datum was used to measure elevation (altitude) above, and depression (depth) below, mean sea level (MSL).

In 1973, the North American Vertical Datum of 1988 (NAVD 88), superseded NGVD '29. NAVD 88 is based upon an equipotential definition and a readjustment.

​We monitor environmental conditions at more than 50 locations throughout Thurston County.  In many cases, we build the gauges ourselves. It's more cost-effective to do so, and we can place them in rugged terrain to survive the elements.