Codornices Creek runs from the hills of Berkeley, California where its headwaters feed from the little valleys and ravines of Grizzly Peak Ridge. From there it flows down out of the hills, through several city parks, and then down through much of urban Berkeley all the way to the San Francisco Bay where it has its terminus just north of the Golden Gate Fields racetrack. The whole watershed drains about 1504 acers (Figure 1) which results in from three to thirteen cubic feet per second of water to flow out of the mouth of Codornices Creek each year.
Let’s take a walk through this watershed, a walk that will move through space an time. What happened along the banks of this creek, and what is happening now? Who and what lived in and used this watershed, and who and what is living here and using it today?
The Ohlone Indians arrived in the area sometime before 500 C.E., and lived along this creek. In the upper areas of the watershed, they hunted deer, rabbit, and squirrel. They also collected the nuts of Bay Laurel trees and acorns for food. Later, the Spanish, and even later Mexicans, granted the whole area as part of the Rancho San Antonio. It remained a rancho until Americans stole or bought the land after gold was discovered in California. Today, deer still live in the hills around the headwaters, as do rabbit and squirrel, although the species of squirrel had changed from the native Western Grey Squirrel to the invasive Eastern Fox Squirrel. Both Bay Laurels and Oaks are still producing their seeds. However, more has changed than the species of squirrel. Several non-native plants have been introduced that are quite different from anything the Ohlone would have lived with. Eucalyptus trees, Scotch Broom, and English Ivy all now are making impacts on the native habitat. Further, many animals that the Ohlone might have encountered are gone. The Mountain Lion could still be found in the watershed, but in far smaller numbers than historically would have been here, and the Grizzly Bear used to roam through this area in large numbers, but does so no longer.
At the bottom of this area of mostly untrammeled habitat, the creek enters several city parks. These are almost a transitional zone between the open space of the watershed above and the suburban and urban areas below. These parks have left the creek alone. They have worked with or around the water for the most part. Codornices Creek Park is where the headwaters all join to become the unified Codornices Creek that flows the rest of the way.
One section in this stretch of watershed that is not owned by the city is owned by the Beth El Temple. On this land the creek has undergone quite a bit of change. When Beth El purchased the land, neighbors were concerned for future of the creek, and as part of the sales settlement the temple was required to develop a plan that would limit damage to the creek during construction. However, during construction, a significant amount of sediment was released into the creek. To prevent further sediment releases, and to lessen the impact that the construction was having on the banks of the creek, Beth El decided to move the entire creek bed. They re-dug a stream channel, diverted the flow, and then began to replant the new banks with native vegetation. All of this at considerable cost, no doubt.
Once the creek flows into more urban areas of Berkeley, it begins passing through a series of daylighted sections and culverts. Most of the way to the bay the creek is daylighted. It is culverted only where it passes under a cross-street making it the most open creek in the east bay. Most of the path of the creek is on private property and, between streets, there is still quite a bit of vegetation on the banks as the creek runs between houses and through yards. However, even though the creek is open to the sky along for most of its length, that does not mean that it is in is natural state now. This entire region of Berkeley used to be the flood plain of Codornices Creek. Now, retaining walls that alter and redirect the flow of water, concrete creek bottoms that reduce available habitat, and limited room for the creek bed to meander have all changed the hydrology of Codornices Creek substantially from when the Ohlone and Spanish would have seen it. All these changes cause the creek to flow faster now than in times past. Faster flow means more incising of the bed, more erosion, and more debris carried by the water. Further the creek is completely culverted when it passes directly under Martin Luther King Jr. Junior High School.
While there are no large open areas where smaller tributary streams can flow into Codornices Creek in such an urban environment, this does not mean that the creek has no water flowing into it from this area. The city streets are still part of the watershed, and the runoff from them carries pollutants, both chemical and solid, with it into the creek.
At the lower end of the watershed, the creek passes under the railway track, where it is open, and under I-580, where it runs through a culvert. From there it then flows out into a small marsh next to the Golden Gate Racetrack. Down along this section of creek, the Ohlone used to catch Steelhead Trout, and some of these fish can still be found in the lower section of the creek. Then, finally, Codornices Creek comes to it’s terminus at the bayshore where it flows into a tidal mud-flat.
These fish, along with frogs and other amphibians, many birds and several mammals are all reminders that there is still wilderness in Codornices Creek, and it needs support and protection. This work is being done by local non-profit organizations such as the Friends of Five Creeks and the Urban Creek Counsel. These groups have worked to restore habitat and water quality along the creek and are continuing to monitor many aspects of the effects that humans are having on the Codornices Creek watershed.
References:
– The Codornices Creek Watershed Restoration Action Plan (2003). From the Live
– Oak/Codornices Creek Neighborhood Association. Available at http://loccna.katz.com/creek/ActionPlan-Kier.html
– FrogWatch USA (2003). From the National Wildlife Federation. Available at
http://www.nwf.org/frogwatchusa/display.cfm?showState=ca&showSite=135
– Live Oak to Tamalpais Walk (1998). From the Berkeley Path Wanderers Association. Available
at http://www.berkeleypaths.com/walkhandouts/walk_LiveOakToTamalpais.htm
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