The Jasper Ridge Biological Preserve (JRBP) water quality-testing program started in January 1998, at one site, under the direction of the Coyote Creek Riparian Station (CCRS). Six other sites in the San Francisquito Creek upper watershed were tested from November 1997 to November 1998; data are contained in the San Francisquito Creek Upper Watershed Volunteer Monitoring Project 1997-98 report. The Jasper Ridge test site was the bridge below the dam, now Site 1. docents completed tests every other week from 12/17/97 to 11/28/98 at 9:30AM on Saturday morning. The CCRS project was completed in 11/98. The Jasper Ridge water monitoring team decided to continue testing independently within the Preserve. JRBP testing began 3/26/99. Tests are conducted every two weeks on Friday at 3:30PM. Data is collected for air and water temperature, dissolved oxygen, conductivity, pH, and turbidity. The three test sites are: Site 1, the original site at the bridge below the dam Site 2, off of the causeway bridge between middle and lower lake Site 3, off of trail 12 in the Corte madera streambed by the staff gauge.(a map of the test sites has been included at the end of the report) During 1999/2000 testing was performed by a team of 5 JR docents: Marge DeStaebler, Claire Elliott, Linda Wager, Alan Weiss, and Cindy Wilber. The goal of the monitoring is: To collect baseline data on water quality and chemistry at specified sites within the JRBP watershed To identify relationships between the variables that we test. To identify relationships between our data and observed changes in the creek To collect data in a format that can be used comparatively with other creek monitoring groups. Data is collected onsite as each test is completed and at the conclusion of all tests, is recorded on a spreadsheet which is then transferred to an Excel database; anomalies are noted if they occur. The updated Excel database is sent electronically to all members of the water monitoring team with the data from all 3 sites, which provides another opportunity to note anomalies, the similarities and differences between the sites, and possible transposition of data errors.