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The Assessment The Watershed Physical Description Land Use The Scotts Creek Watershed Council The Salmonids Habitat Restoration & Conservation Projects Events Newsletter Contact Us |
The AssessmentDescriptionThe Scotts Creek Watershed Council undertook the production of a “Watershed Assessment” and resultant anadromous salmonid habitat improvement project recommendations using, in part, funding from a SB271 grant administered by CDFG. The project was undertaken to assess current conditions in the context of the historical, geological and hydrological setting. Current restrictions to land development are also assessed. One of the primary goals was to identify and describe potential salmonid habitat restoration and enhancement projects. The Assessment document is not intended to be a management, land use or habitat conservation plan. Projects identified are intended to be suggestions for ongoing cooperative efforts and are not intended to be binding in any way. By compiling and comparing current scientific studies and empirical surveys, the assessment attempts to evaluate the health and function of the watershed system. The identification of projects was based on the findings of numerous studies, surveys, observations, and local knowledge. Unlike many watershed assessments, the process employed in the creation of this assessment did not include the acquisition of any new data. There was not sufficient funding to fill in gaps in empirical and scientific knowledge. Areas needing further study were identified as potential projects. Several Watershed Council members, professionals in relevant areas of study, contributed reports on various aspects of watershed conditions. In this they were also were assisted by members of the SCWC Technical Advisory Committee. | ||||||||||||||||||||||||||||
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Assessments of specific issues have been undertaken, including identification of sediment sources, fish barriers, non-native species populations, water use, and historical versus current land uses. In addition, data have been summarized on various relevant subjects including geology and geomorphology, hydrology, in-stream salmonid habitat, aerial photographic sets, and stream profiles. Species lists of watershed biota were compiled. Developed by the Scotts Creek Watershed Council, this watershed assessment is the culmination of six years of work including much discussion and a compilation of hundreds of hours of research. The characterization of the watershed function and form has been performed by a large and diverse group of professionals including geologists, hydrologists, biologists, engineers, foresters, historians, planners, and resource managers. Executive SummaryThe assessment that follows reflects the efforts of community and technical advisory committee members dedicated to understanding and caring for the environment through the tools of natural science. We thank these people for their crucial commitment, both to this process and to the Scotts Creek Watershed Council. Assessment of the Scotts Creek watershed reveals a regime of high frequency, high intensity disturbance events that have always characterized this terrain. The local ecology evolved in this setting of fire, landslides, debris flows and precipitation irregularities. The exceptional species richness of the flora of the watershed likely reflects the disturbance frequency as well as geologic/geographic factors. While disturbances provide an opportunity for plant species to pioneer in new locations, frequent disturbances can affect salmonid population stability. Natural variations in fish habitat quantity, quality, and accessibility relate directly to rainfall in the watershed. High levels of background sedimentation are normal and natural here. The predominant highly fractured and/or weathered bedrock is easily eroded by the high intensity rainfall characteristic in this region of steep terrain. Mudstone gravels recruit at a fairly high rate. The exceptionally low specific gravity of this rock coupled with the characteristic blocky and disk-shaped gravel it forms causes it to be scoured by relatively common increases in flow. Redds formed in this gravel are easily scoured out. Granitic rocks are more common in the upper watershed and in most of Big and Little Creeks. The granitic gravels are more stable in the streambed. Fluctuations in the timing of the wet season and wave action result in occasional limited accessibility to the Scotts Creek system. This challenge has a far greater impact upon coho (Oncorhynchus kisutch) than on steelhead (Oncorhynchus mykiss). Coho begin massing for a concentrated spawning run in December. When winter storms are late, access to the creeks is delayed and coho are lost to predation. If flows are sufficient to permit coho entry, the success of spawning attempts can still be curtailed later in the season by redd-scouring high flow events. Steelhead population numbers in the Scotts Creek system are considered to be relatively stable. Steelhead spawning runs extend much later, resulting in greater chances of success. Creeks are more likely to be accessible as these fish arrive, and redd damage due to high-flow events is rare late in the season. The Scotts Creek and adjacent watersheds define the extreme southern range of coho salmon today in North America. Coho salmon are a relatively short-lived species (about three years). The reasons for the apparent coho population decline in Scotts Creek are somewhat uncertain. In order to help sustain the species in this watershed until the reasons for the population decline are more completely understood, some projects have been proposed to mitigate downturns in habitat quality that are part of natural cycles or caused by natural events. In the last 200 years the Scotts Creek watershed has undergone several human-induced transformations. The effects have, for the most part, not been quantified, but the prevailing supposition is that salmonid habitat may have been degraded by human activities. Evidence of early resource extraction practices, fisheries management, and other human activities is present in the watershed, with logging and fish planting throughout much of the watershed and other activities more localized. Some effects of these activities may still be significant to the quality of salmonid habitat. To the degree that negative effects were identifiable, they are addressed in the Assessment and restoration/enhancement or mitigation projects are identified. The current state of ecological recovery reflects a reversal of development trends. Current land use practices (including the use of water) are intended to prevent negative impacts to salmonid habitat. Opportunities for further refinement of management practices are actively sought. Watershed residents and land managers agree that any restoration/enhancement activities must be based upon sound, peer-reviewed science that clearly applies in the specific context of the Scotts Creek watershed. Potential for future human development in the watershed is extremely limited by a wide variety of political and regulatory constraints. Proposals able to win regulatory approval are highly unlikely to impact salmonid habitat, and the outlook for continued exemplary land stewardship in this unique system is good.
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