UC Berkeley Course LA 227 Research at Blake Garden

Posted on by meghanray@berkeley.edu

Blake garden is bounded on the north and south borders by upper reaches of Cerrito Creek. These water channels create an excellent opportunity for ongoing research in creek dynamics. The UC Berkeley course "River and Stream Restoration” offered each fall and taught by fluvial geomorphologist Prof. G. Mathias Kondolf provides students with the chance to study riparian systems out in the field. Student research at Blake Garden has ranged from site surveys to restoration planning. The opportunity to build a body of research over time is a major benefit of the relationship of Blake Garden to the main campus.


Some student research papers on the Blake Garden creek reaches include:


Restoration With Reference: Rediscovering Cerrito Creek in Blake Garden (Ludy, Jessica and Podolak, Kristen, 2007)


This investigation focuses on potential improvements to the Blake Garden section of Cerrito Creek for both ecological and social reasons. Cerrito Creek runs through an urbanized watershed from the East Bay Hills to San Francisco Bay. Garden staff recently cleared non- native invasive Himalayan blackberry (Rubus discolor) from several sections of the streambank, leaving it barren. We identified bank erosion and incision resulting from recent clearing and upstream urbanization as two issues to be addressed. The garden staff identified creek visibility and accessibility as their main concerns. To assess existing creek conditions and restoration objectives we completed longitudinal and cross sectional surveys, measured discharge from an on-site spring, and conducted interviews. We calculated creek discharge using the rational method, measured the surface area of two rooftops to estimate stormwater runoff, and measured discharge from a natural spring in the garden. Based on our assessment, we developed a creek restoration plan that addresses the hydrologic issues we identified, concurrently with those set by the garden staff. Our short-term recommendations include: jute netting and stream-bank plantings to stabilize the banks, constructing a step pool to reduce energy and provide an aesthetic water feature, and installing rain and stream gauges. Long-term recommendations include: geotextile reinforcement and regrading steep banks to improve access and safety, replacing downstream check dams with step pools, removing concrete (substituting alternative stabilization measures), reducing stormwater runoff onsite, and water harvesting from the natural spring. Future studies should monitor the rate of incision, evaluate the effectiveness of restoration measures, and assume an adaptive management approach. 



Cerrito Creek step-pools: An opportunity for restoration and education at Blake Garden (Behrends and Nathaniel, 2008)


The focus of this proposal is to examine relevant creek restoration research and existing restoration projects and to apply the resulting knowledge to the specific conditions at Blake Garden to develop a conceptual model for the restoration of this section of Cerrito Creek. This proposal builds on goals and data that were compiled as part of a prior student restoration proposal. A literature review, case studies, interviews and a site survey provide data about the restoration of similar creeks, future visions for Cerrito Creek and existing creek conditions. Based on the compiled data, a system of step pools is recommended to restore channel stability in this reach of the creek. Channel geometry is based on a restoration model with similar characteristics, Baxter Creek in Pointsett Park. Step pool geometry is determined using a ratio between step height, length and channel slope. Channel visibility and physical access are revealed as important aesthetic concerns. Recommendations are summarized in a conceptual design proposal that integrates the restoration objectives with the existing site conditions. 



Towards a Stable Future: A Design Proposal for Cerrito Creek in Blake Garden (Greenberg, Pinto and Sherraden, 2010)


An upstream reach of Cerrito Creek, in Contra Costa County, California runs through Blake Garden, a 10.5-acre demonstration garden owned by the University of California, Berkeley (Fig 1 & 2). This study focuses on a 420- foot reach near the top of the garden that has a severely incised and undercut channel, undersized and deteriorating culverts, and failed bank armoring. In the spring of 2010 for LA222: Hydrology for Planners, the authors of this paper analyzed the hydrology of the watershed above the reach, in order to understand the flows that are likely causing incision, conducted extensive field surveys, and modeled flow in the creek. Continuing with last semester’s work, we conducted a detailed facies map, and identified constraints and opportunities along the stream channel. Permanent monuments were placed on the site, and accurate mapping of the reach and cross-sections was generated. Based on our cumulative understanding of the site, we propose a stream design that will arrest incision and bank failure while allowing the 100-year flood to be conveyed through the channel by either reducing velocity below scouring or by protecting the banks. We achieve this by creating step-pool sequences in the actively incising sections, connecting the channel to a floodplain where possible, and proposing bank protection where the channel is more constricted. The design follows our goals of enhancing wildlife habitat, and serving as an attractive design element and educational focus within Blake Garden. 



Comparison of Winter Creek and Cerrito Creek: How Institutional Factors Determine Intervention Strategies (Eason, Miriam, Gonzalez and Daisy, 2013)


Our research outlined institutional and physical similarities between Winter Creek and Cerrito Creek and as- sessed the 2009 Winter Creek channel stabilization and enhancement to determine if it was successful and could be a precedent for a Cerrito Creek intervention. Winter Creek and Cerrito Creek are intermittent San Francisco Bay Area East Bay streams that share geomorphological and institutional factors. Both streams are especially valuable assets because they are located within University of California, Berkeley gardens and they are some of the only open channel streams in their watershed. However, their steep upper watershed locations combined with upstream development and primarily clay soils have led to extensive erosion and incision (Stewart & Wickland, 2005; Jewell & Norcross, 2007). Our Winter Creek cross section profiles compared with ESA-PWA 2009 post-restoration cross sections indicated that Winter Creek has remained stable and project goals of channel stabilization and flood control were achieved. We compared geolog- ical, watershed context, ownership, and permit requirements of Winter Creek with Cerrito Creek and determined that the two creeks were similar enough that Winter Creek could be a precedent for a similar channel stabilization and flood control project at Cerrito Creek. Through interviews and photographic assessment we determined that Cerrito Creek is in need of a serious channel stability intervention, however funding is not currently available for a project of Winter Creek magnitude (Tim Pine, UCB Office of Health and Safety, personal communication 2013). We recommend a Cerrito Creek feasibility study to identify opportunities and constraints, costs and potential funding sources to move towards channel stability and flood management and enable this creek to remain a valuable asset. 



Finding a Foothold on an Uncertain Bank: An Assessment of Cerrito Creek in the Blake Garden (Lopez, Chen, Cole, Howe and Mahmoud, 2019)


An open reach of Cerrito Creek flows through The Blake Garden, owned by the University of California, Berkeley (UC Berkeley). The Blake Garden acts as a “landscape laboratory”, available for students and employees for experimentation in horticulture, creek restoration, and landscape architecture. Prior evaluations (since 2007) of the stability and behavior of the upper section of the reach of Cerrito Creek (the ‘Upper Reach’) have reflected diverse perspectives and made ambitious recommendations for creek improvements. We developed a comprehensive baseline that can serve as a reference for future studies by both students and staff at the Blake Garden. We surveyed a long profile through the reach, and built upon prior surveys. We compiled data on the natural history and physical setting of the Upper Reach, determined the catchment area of the upper reach, identified and analyzed influent sources, described the extent and dynamics of the floodplain, measured physical characteristics, and exhausted existing literature and eyewitnesses. 



What’s Past is Present: A Re-Evaluation of Cerrito Creek in Blake Garden (Sasaki, Wang, Yang, 2018)


A 2000-foot-long reach of Cerrito Creek runs through the University of California, Berkeley-owned Blake Garden. Past student groups have conducted surveys and hydrologic studies on this reach and in a 2010 study suggested recommendations for restoration. In this study, we assessed current creek conditions and compared them to the conditions surveyed in 2010 to determine whether the recommendations are still valid and feasible. To recreate the 2010 study, we attempted to conduct cross-section surveys at roughly the same points as the previous study. We also 3D modeled this reach on both time nodes to achieve the comparison. We found that most recommendations had not been implemented and as a result, the channel continued to experience erosion and incision. We concluded that most of the recommendations are still valid but must be adjusted to address the current conditions and the financial limitations. Taking all factors into consideration, we agreed that low-cost alternatives like biological stabilization using local riparian vegetation would be the most feasible solution. Therefore we did an existing plant survey of the area along the creek and referenced the prior studies, came up with a plant species list and a planting plan in response to multiple purposes of the restoration plan 



Understanding the Waters/Understanding the Canyon: A Baseline Study of the Redwood Canyon Reach of Cerrito Creek in Blake Garden (Thoma and Solas, 2020) 


This paper establishes    a cross sectional baseline of the Redwood Canyon reach of Cerrito Creek in Blake Garden to be compared with future surveys and to assist with any decision making about the area by garden staff. We created a topographic survey of the main stream channel, historical and potential side channels and tributaries fllowing from neighboring properties. While the main stream channel is stable with a low seasonal flow, water entering the property from neighboring Jessen Court is sustpected to have caused damage leading to the removal of 2 large Redwoods and has the potential to cause more damage if these tributaries continue to incise and migrate.  


For full text of the above papers see: https://escholarship.org/uc/wrca_restoration/search?sort=desc&rows=10&start=20 or https://escholarship.org/uc/berkeley_riverlab_studentpapers/search?sort=desc&rows=10&start=10