Water Resources Collections and Archives

Lehi Park in Santa Cruz County is preparing to submit a long-term sustained yield timber harvesting plan (Non-industrial Timber Management Plan or NTMP) to the California Department of Forestry and Fire Protection for a portion of the Scott Creek Watershed. This portion of Scott Creek hosts a population of Rainbow Trout; the landowner wants to retain those trees that will contribute to pools with adequate structure to provide cover for trout.

We observed and described large woody debris and its orientation in the channel of Scott Creek and its effect on sediment storage and conveyance, as well as channel form; and we developed baseline data for water quality monitoring for the NTMP.

We surveyed a longitudinal profile (of the thalweg, water surface, and high water mark) and four cross sections, made fourteen sediment depth readings along the channel, and made several field sketches and took pictures to document the effects of large woody debris on channel form. This baseline data, in conjunction with regional hydrographs, allowed us to estimate the return interval of the measured high flow, which is approximately 1.5 years.

Our observations of large woody debris may contribute to future study and possible recommendations for bank-side tree protection. Lastly, this baseline data may become useful in subsequent surveys as a demonstration of change in stream profile over time.