Water Resources Collections and Archives

Aquatic ecosystems in the Upper Klamath Basin (Upper Basin), Oregon are degraded as a result of more than a century of land use alterations due to logging, dams, irrigated agriculture, and cattle grazing. These changes have led to degraded habitat conditions including decreased baseflow, loss of vegetation, increased stream temperature, fish impediments, and nutrient loading. All these factors negatively impact watershed function and resident fish populations, which have experienced severe declines in recent decades. The primary threats to fish populations include habitat loss, degraded water quality, barriers and entrainment, and predation and competition from non-native species. Millions of dollars have been spent since the late-1900’s to restore aquatic habitat in the Upper Basin primarily to improve the distribution and abundance of endangered and threatened fish species. This project details the hydrologic characteristics of three primary tributaries in the Upper Klamath Lake Sub-Basin including Sevenmile Creek, Wood River, and the Williamson River (including spring tributaries). Available discharge data was assembled to plot seasonal fluctuations in flows and identify annual peak flow at different re-occurrence intervals. Stream systems in the UKL Sub-Basin show a range of hydrologic inflow due to groundwater and/or snow-melt run-off. Characteristics of spring-fed vs. run-off dominated stream systems are reviewed and recommendations are made for how to address restoration practices considering the hydrologic and geomorphic characteristics of stream channels.

Our study attempts to assess how different methods of engaging student volunteers on Berkeley’s campus impact student’s enthusiasm for stewardship, such as their willingness to participate in future on or off-campus restoration projects.  Using a questionnaire and targeting four different undergraduate student groups, including students who lived adjacent to Strawberry Creek, we attempted to gauge their current involvement and future involvement in stream restoration activities.  We found that academic work is the strongest method of engaging student volunteers and that some form of spontaneous use is the best indicator of each student’s enthusiasm for future stewardship. In summary, student stewards can provide the link between academic solutions and collaborative engagement with urban creeks.

In Fall 2010, a partnership between the University of California-Berkeley and the cities of Albany and Berkeley completed the third of four restoration phases planned for a 0.6-mile stretch of Codornices Creek in Alameda County, California, between the San Pablo Avenue and UPRR crossings. Originally initiated in the mid-1990s to improve a straightened and channelized ditch, the project objectives were to convey the 100-year flood, improve user access to the creek, and establish an ecologically valuable riparian corridor dominated by native species (reducing invasive non-natives).  We assessed the performance of the third phase of the project during a high flow of 136 cfs on October 5, 2011. We obtained relevant data and information from project designers, and on October 22, 2011, while evidence of the high flow was still fresh, we conducted a detailed topographic survey of the channel, surveyed high water marks, documented conditions with photographs, and mapped site conditions. In addition, we surveyed cross sections and high water marks in the downstream reaches (Phases 1 and 2 of the overall restoration project).  High water marks show floodplain inundation was inconsistent throughout the three reaches, with the October 5 storm flow largely staying within the constructed banks in Phase 3, and overbank flow occurring in Phases 1 and 2.   Our longitudinal profile shows Phase 3 incised up to 2 ft below the design grade in the upstream portions of the reach, and aggraded up to 2 ft at the downstream end. Survey results also confirm that additional vertical channel adjustment occurred during the October 5 flow. This, along with the presence of an active headcut, suggests that the channel is still in the process of finding geomorphic equilibrium. Cross-section monitoring in Phase 3 should proceed into the future to determine whether channel adjustments continue, and as a basis to assess whether more complexity should be introduced to promote aggradation, channel complexity, floodplain inundation, and more ecologically valuable habitat. 

ABSTRACT

A 700-foot-long daylighted reach of Cerrito Creek defines the southern border of the 29-acre El Cerrito Plaza shopping center and receives a majority of the Plaza’s stormwater runoff. In 2003, this reach, between Talbot and Kains Avenues, underwent a restoration project that widened, re-graded and re-vegetated the channel as well as added a gravel pedestrian path parallel to the stream. The project was completed while the shopping center and parking lot underwent a major renovation. In this study, we assessed current creek conditions and compared them to the original project design as well as a 2005 post-project assessment. We found that there may have been minor channel incision since 2005, but this evidence was unreliable due to the cross section locations having not been permanently monumented. An increase in the number  of gravel bars, and an increase in the diversity of sediment size indicated that the stream was transporting sediment. Native vegetation planted during the restoration appeared to be flourishing, although we documented a few invasive species that have established as well. Although the creek restoration was successful at creating wildlife habitat and a new amenity for the public, it did not address the treatment of stormwater, raising concerns about the impacts of potentially harmful urban runoff on creek water quality. We considered options to retrofit stormwater management infrastructure and concluded that flow-through biofiltration structures such as sand filters, basins, or planters would be most feasible based on the local soil conditions and available land area.

Livestock grazing in the western United States has lead to riparian ecosystem and stream channel degradation. Establishing fenced-off exclosures is a common management strategy that aims to passively restore these areas, however, relatively few studies have assessed the evolution of exclosed reaches over time. We evaluated temporal trends in channel form and riparian vegetation along a 4.2 km reach of Long Creek (drainage area of 180 km2), a tributary to Sycan Marsh in western Lake County, Oregon. The Nature Conservancy implemented reduced livestock grazing along this reach in 1996 and complete exclosure in 1999. Based on previous studies that documented vegetation establishment and subsequent sediment accumulation on channel banks, we hypothesized that the channel would have narrowed and vegetation would have re-established after eleven years of cattle exclosure.   In October 2011, we surveyed seven previously-established cross sections and compared channel geometry in 2011 to surveys conducted since 1990. We also took photos at these locations and compared them to historical images. We found no consistent trend in channel morphology, but two cross sections demonstrated narrowing, one of which was likely driven by reduced flow velocity from a downstream beaver dam. Vegetation had successfully established along the streambanks, but in addition to the riparian species, upland lodgepole pines were also abundant along the channel and on the floodplain.  Our results suggest that beavers should be encouraged so their dams will increase overbank flow and discourage the invasion of upland plant species. We also propose improvements in monitoring methods to ensure repeatability of cross-sections over an extended monitoring period.