Lost Man Creek Streamflow and Turbidity Monitoring
Lost Man Creek is a significant tributary to Prairie Creek, which in turn is a tributarty to Redwood Creek. Like most of the redwood forest in northern California, the watershed was heavily logged prior to implementation of the state's forest practice rules. Logging between teh 1950's and the early 1970's consisted of large clearcuts, tractor yarding, and unregulated road building. These activities led to widespread erosion and sedimentation during large flow events such as those that ocurred in 1955 and 1964.
In 1978 Redwood National and State Parks (RNSP) initiated a watershed restoration plan in order to reduce erosion and sedimentation of streams, and to restore the natural ecosystems to conditions similar to what would have existed before timber harvest and road building ocurred. In order to reduce erosion and sedimentation RNSP has focused heavily on road removal. Road removal within the state and national park is accomplished through excavating stream crossings, re-contouring of road beds, and restoration of historic drainage patterns.
In 2003, as part of the watershed restoration plan, a monitoring plan was developed that included monitoring turbidity and suspended sediment concentration at newly removed stream crossings as well as at numerous downstream locations. GMA worked in coordination with RNSP staff from 2003 through 2011 to modify and improve the monitoring program. 'On site' turbidity monitoring of road crossing removal sites, non continous turbidity and suspended sediment monitoring, and five continous streamflow and turbidity monitoring stations were operated at various times throughout the duration of the project. GMA performed all operations of the continuous monitoring sites including; maintaining onsite equipment, maintaining accurate stage versus discharge rating curves, performing storm related suspended sediment sampling, analyzing suspended sediment concentration samples and providing final computed streamflow values.
GMA and RNSP's long term monitoring activities in the Lost Man Creek Watershed allowed RNSP to assess the effects of road removal restoration activities on downstream turbidity and suspended sediment concentrations. In addition, monitoring has provided adaptive management feedback for refining erosion control methods used by RNSP during road removal activites.