Putah Creek, running from Lake Berryessa in the Blue Ridge Mountains to Yolo Bypass Wildlife Area acts as a divider between Yolo and Solano County. Once a vibrant source of habitat for a variety of organism with miles of riparian forests, floodplains, and wetlands, it now is a dammed and controlled creek with the main purpose of providing water to the public and private agricultural lands. The main goal of our design is to create a viable wildlife corridor that connects the coastal mountains to yolo bypass and allows access and movement for migrant deer and other focal species. The intent of our design is to increase human involvement along the creek through recreational and educational opportunities while also catering to the needs of our six focal species, the California Ground Squirrel, Osprey, Chinook Salmon, Giant Garter Snake, Mule Deer, and the American Beaver. To gain a better understanding of key features along the greenway, an emphasis was placed on the three distinct reaches of the creek. Reach 1, extending from Stevenson Bridge Road to the North/South Fork split, Reach 2, the northern fork of Putah Creek, and Reach 3, the southern fork of Putah Creek, have all been analyzed from an ecological and cultural standpoint and then designed to best suit human and animal needs.
Land ownership, transportation routes, water stations, and historical landmarks were mapped and data of different recreational activities of the area were taken into account. The creek and the adjacent properties are used today for farming and for activities including but not limited to fishing, camping, hunting, biking, and swimming. From there, a cultural inventory map was developed and analyzed.
With a cultural inventory map, the opportunities of the area were analyzed. Drawing people to the creek through recreational opportunities and historical landmarks allows for greater use and protection. Landmarks can be neither moved nor altered but they do pose the advantage of providing a sense of history to the area. Bike paths, especially the Davis Bike Loop, have been viewed as an opportunity. This created design expands on existing bike trails, connecting the different forks of the river to the Davis Bike Loop.
Constraints of the area were also analyzed and addressed. Most of the surrounding area is privately owned agricultural land and, as a result, constructing a greenway would be impossible without the approval of the landowners. Highways also pose a constraint as heavy traffic flow is dangerous for human movement. As the years progress and land ownership changes, the goal of this design is to bring the greenway as close to the creek as possible, expanding its entire length.
To begin collecting ecological data, six focal species were selected whose presence would be essential to greenway design. This selection process began with identifying threatened and umbrella species native to Yolo and Solano County that use Putah Creek and its source habitats (Coastal mountains and Yolo bypass) as a habitat. The California Wildlife Habitat Relationships database was used in choosing focal specie. A species matrix was created to show the different habitat types of each animal, allowing one to predict how each species would move in and occupy a given area. With this knowledge, a structural design for each species was implemented. With the information from the matrix, suitable areas for each species were mapped by analyzing opportunities and constraints. Opportunities for each species consist of areas that they are most likely to use. Constraints consist of areas the species would not be able to use because of either human intervention or due to the fact that specific habitat types offer little or no benefits for that particular species. Once opportunities and constraints were established, hotspots for each individual species were located. Hotspots are areas that were most suitable for that particular species. After opportunities, constraints, and hotspots for each species were mapped out, we were able to see where each species would intersect. These areas of intersection were the main candidates for creating nodes and stepping stones in our greenway design.
With maps displaying both social and environmental findings of the area, the sets of data were combined in the efforts to create a most effective greenway. Reach 1 caters to the needs of all six focal species through habitat restoration and the development of a reserve. Restoring grasslands, forblands, and meadows creates wildlife corridors and hedgerows for increased functional connectivity. In addition, access points allow for human recreational use and path connectivity. Designated recreational activities allow for a variety of cultural uses without harassing or interfering with wildlife. Vistas and viewing platforms made from recycled materials allow for people to submerse themselves in the beauty of nature while also allowing for educational opportunities through kiosks, maps, and information plaques strategically located throughout the greenway.
Different recreational opportunities, such as camping, boating, hiking, and fishing, can also be found along this reach by the designated recreational area. Glide Park Ranch will serve as the main hub of the reserve, acting as a visitor’s center and high-end restaurant made possible through the cultivation of site-grown and local foods.
The goal of Reach 2 was to increase wildlife movement while also considering the hydrological history of this site. The North Fork has been disconnected from the main stretch of the creek; therefore, the design proposes that the two portions of the creek be reunited through the use of a pipe and pump running along a constructed wildlife and pedestrian overpass. This overpass will stretch over Highway 113, allowing for safe passage of both pedestrians and animals simultaneously. Lastly, Reach 2 also allows for the implementation of vernal pools between Highway 113 and Interstate 80.
Bike circulation has been designed to continue throughout Reach 2 and wineries have also been added to increase human use and involvement. Bike paths have been added to connect with the Davis Bike Loop, connecting Davis to the rest of the greenway.
The goal of Reach 3, the Southern Fork of Putah Creek, is to create a wetland that provides ample and adequate habitat for wildlife. This wetland, receiving much of its water from the Arboretum located within the University of California Davis campus will work as a filter, purifying water through natural ecological and hydrological processes before entering into Putah Creek. The design of topography of the wetland sustains wildlife by creating both sources of cover and food.
Natural visual and sound barriers have been set into place to reduce human impact to the wetland-residing animals. Kiosks will allow for additional educational opportunities as people gather in vistas and overlooks. Bike paths will also continue throughout the site allowing for a full connection between the westernmost end of Reach 1, Reach 3, the town of Davis, and the Yolo Bypass Wildlife Area of Reach 3.
While designing the Putah Creek Greenway, Steve Greco of the University of California: Davis acted as a mentor due to his experience with landscape ecology, Putah Creek, and landscape design. Greco provided articles and research to help inspire land use design and potential.
Rich Marovich counseled the greenway design with his ecological expertise and knowledge of Putah Creek and the town of Winters, the only other town that lies directly adjacent to the creek, aside from Davis. Rich provided cultural and ecological information of the site as well as historical information.
Rob Thayer, founder of the Landscape Architecture program at the University of California: Davis, provided design feedback as a guest critique. Rob provided cultural facts about the site and also studied the design aspects of this proposed greenway.
The Putah Creek Greenway was designed and completed by Carson Cooper in collaboration with several other UC Davis landscape architecture students: Ying Ying zhong, Micheline Chagniot, Brooks Taylor, Gabriel Munoz, and Hoang-Lan Nguyen. We made an awesome team.