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.

Abstract

Putah Creek (drainage area = 2,000 km2) drains the slopes of Cobb Mountain in Lake County, flowing 137 km southeastward into the Yolo Bypass near Davis, California. Lower Putah Creek, the 37km reach from the Solano Diversion Dam to the Yolo Bypass, is confined within a flood control channel.  Dry Creek (drainage area = 44km2) joins Putah Creek near Winters, California.  Putah Creek is regulated by water releases from Monticello Dam at Lake Berryessa.  Dry Creek flows only part of the year and has no dams. Southward channel migration of Putah Creek from the 1990’s was threatening Putah Creek Rd., a paved county road following the south bank of the evaluated stream-section.  The new location of the Putah Creek channel also reduced the amount of gravels entering Putah Creek from Dry Creek.  This was significant because dams reduced the amount of course sediment available from upstream, leaving Dry Creek as one of the only natural sources of the gravels important to the ecology of Putah Creek. In 2005, the Lower Putah Creek Coordinating Committee implemented a project to move the channel of Putah Creek northward to its approximate historical course.  The project included the removal of invasive giant reed (Arundo donax), in part because Arundo appeared to have contributed to the unwanted channel avulsion.  We evaluated the project performance towards the goals of 1. protecting Putah Creek Road, 2. keeping invasive plant species out of the area, 3. facilitating natural transport of Dry Creek gravels into Putah Creek, and 4. improving salmonid habitat.  Our evaluation found that 1. Putah Creek has stayed within the general path of the design channel and is not returning to the southern pre-1997 channel which threatened the road, 2. there is a mix of native plant species (e.g. willow, cottonwood) and invasives (e.g. Arundo, blackberry) in the floodplain, 3. There is no physical barrier separating Putah and Dry Creek, 4.  the channel and floodplain provide good habitat complexity for native fish, but fine sediments cover most of the potential spawning gravels.

In  California’s  Central  Valley,  dams  block  95  percent  of  historic  salmonid  habitat.    To  restore access by spring-run chinook salmon (Onocorhynchus tshawytscha) and other anadromous fish to approximately 12 miles of upstream spawning habitat on Clear Creek (drainage areas 720 km 2 ), the  US  Bureau  of  Reclamation  removed  the  McCormick-Saeltzer  Dam  in  November  2000.Previous  studies—the  most  recent  in  2004—identified  significant  sediment  mobilization  since dam removal at, and above, the former dam site.  In October 2011, we resurveyed two previously established  cross  sections at 26  m and 103.3  m upstream  of  the  dam  site  and  conducted  a  long profile  of  the  thalweg  from  the  dam  site  to  175  m  upstream.   We  also  replicated  previous  site photographs,  drew  vegetation  maps  and  compared  2010  aerial  photographs  to  those  from  1998 and  2004  to  assess  vegetation  change  and  erosion  patterns.   Our  results  documented  little incremental  erosion  at  and  upstream  of  the  dam  site  since  2004,  suggesting  that  sediment mobilization post-dam removal has largely stopped.  Establishment of riparian vegetation may be stabilizing remaining sediment deposits.

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.

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.