«A thesis submitted to the faculty of San Francisco State University In partial fulfillment of The requirements for The degree Master of Arts In ...»
Scott Holmes) estimated that Phases I, II, and III would be completed in 2003, but that the actual date could be moved up if city staff (i.e. Holmes) determined that the flood potential was too great (Larsen 2001).
In fact, Scott Holmes worried that San Pedro Creek was likely to overflow its banks again in late 2002 and decided to move the creek to its new channel one year earlier than planned (Photographs 7-12) (Holmes 2002). Although this cut short the time allotted for the new vegetation to grow in the restored area, the decision may
Kelsey McDonald - Thesis 120PHOTOGRAPH 5.
New Floodplain and Stream Channel, Looking NE, March 2001.
New Floodplain and Stream Channel, Looking NW, March 2001.
Vegetated Floodplain with San Pedro Creek in New Channel, Looking East, Summer 2003.
Vegetated Floodplain with San Pedro Creek in New Channel, Looking East, Summer 2003.
New Floodplain, Looking NW Toward Ocean, May 2004.
10. San Pedro Creek Flowing Through New Floodplain, Looking Upstream, May 2004.
11. New Floodplain, Looking Upstream, May 2004.
12. New Floodplain in Foreground, Homes Behind Berm in Background, Looking NE, May 2004.
have prevented flooding from a winter storm that closely followed the completion of the move (Hall 2003; Holmes 2003b). The winter storm caused flooding for houses on the north bank around Peralta Bridge when water backed up at the bridge (Holmes 2003b).
After the creek was diverted into its new channel in late 2002, Holmes advised residents that work completed on the reach between the Linda Mar Convalescent Home and the Highway One Bridge brought the reach up to a 500-year capacity from the original 4-year capacity estimated by the Corps (Holmes 2003a). However, Holmes noted that despite the increased capacity in this reach, work was still required in other areas in order to reach the 100-year flood capacity, so that homeowners would not have to purchase flood insurance (Holmes 2003a). Holmes later noted that the estimated 25-year flows proved the design was effective; the new berms were high enough and the streamflows deposited gravel in the expected locations (Holmes 2003b).
Work remaining on Phase II that was expected to be completed in July 2003 included removing berms and fill on the western portion and planting in the eastern wetlands (Holmes 2002). Phase III slated for completion in 2004 now included widening the channel from the Peralta Bridge downstream to the convalescent hospital, as well as installing a new Highway One Bridge (Holmes 2002).
By fall 2003 with the exception of the work west of Highway One, the phases seemed to have dissolved into pieces of the project that the city’s Department of Public Works would complete as funding became available. The city hoped to address the
Kelsey McDonald - Thesis 125reach from Peralta Bridge to the convalescent hospital, which was originally part of Phase II, in 2003/2004 (Holmes 2003a). Caltrans decided not to replace the Highway One Bridge, so city staff added it to the city’s list of items outstanding for the flood control project (Holmes 2003a). A separate project to restore Pacifica State Beach now included the flood control project’s work on the area west of Highway One (Photographs 13-14) (Holmes 2003a).
Work on the area west of Highway One was completed in 2003-2004 as part of the Pacifica State Beach Master Plan (Holmes 2003a). By late September 2003 using grants and public funds the city purchased two homes on the beach, which it then demolished (Hunter 2003). After the demolition San Pedro Creek was widened near its mouth, a spit was created to form a coastal lagoon, and approximately two acres of tidally influenced wetlands were restored (Hunter 2003; Larson 2003-2004). The work at the mouth of the creek was completed by early November 2003 (Photographs 15-18) (Holmes 2003b). In early 2004 the Public Works Department addressed the problem of water pooling in the low-lying area north of Linda Mar Boulevard by adding two pumps to its pumping stations to increase capacity by up to ten times the previous capacity (Holmes 2004).
Work remaining as of early 2004 on the flood control project to provide 100year flood protection included channel widening from the convalescent home up to Peralta (Holmes 2003b). The Department of Public Works planned to do this work itself beginning in 2004 or 2005, depending upon when the permits could be obtained
Kelsey McDonald - Thesis 126
13. Near Creek Mouth, Looking Upstream, March 2001.
14. Future Site of Coastal Lagoon, Looking Upstream.
San Pedro Creek flows under the San Pedro Road Bridge (and Highway One Bridge behind it), March 2001.
15. New Coastal Lagoon, Looking South, May 2004.
16. San Pedro Creek Flowing under San Pedro Terrace Road Bridge (and Highway One Bridge). Near creek mouth, coastal lagoon begins on the left, looking upstream, May 2004.
17. New Coastal Lagoon and San Pedro Creek Near Creek Mouth, Looking South, May 2004.
18. New Coastal Lagoon and San Pedro Creek Flowing Into Pacific Ocean, May 2004.
(Holmes 2003b). Public Works hoped to replace the Highway One Bridge (Map 2) in the 2006-2008 timeframe, but that timeframe depends not only upon obtaining funding (Holmes 2003b) but also on gaining public support for the new bridge, which could be difficult, given that opposition to the bridge already exists and that some residents think that the flood control projected has already been completed (Hall 2003). Work was also still outstanding to increase capacity at Adobe Bridge, but no specific timeframe had been established yet (Holmes 2004).
The outcome of the San Pedro Creek Flood Control Project to date has received very positive feedback. Patrick Hall expressed his satisfaction with the outcome, saying that the end product has turned out better than could have been imagined (Hall 2003). Todd Greene noted that the project is good for everyone; the Corps got a flood control project, the city got flood control, and the project area now has lots of wildlife (Greene 2004).
Although many elements influenced the development of the flood control plan, the city - and more specifically the person in charge of the project for the meso-level city, Scott Holmes - most significantly influenced the actual implementation of the plan.
This influence is in large part due to Scott Holmes’ own experiences, values, and goals.
Many people, including committee members and representatives from the Corps, credit Scott Holmes for his flexibility in implementing the plan. Holmes broke the project into phases, because they are easier to fund than funding a single massive project. The phases also allow the project to increase flood protection for some areas, while waiting
representative(s) from the Corps to remove the diversion pipe from the plan, not only made funding more feasible, but also eliminated a potential confrontation with residents along the pipe that could have delayed the project. If the project manager from the Corps had not supported the plan, they may have opposed removing the diversion pipe from the plan. Although the decision to remove the diversion pipe without going back through a public review process may have been outside of standard procedures, this decision allowed the project to proceed. These decisions made by the individuals acting in meso-level roles highlight the individuals’ significant influence on the project outside of the bounds that their meso-level role or meso-level policies set.
Evaluating the San Pedro Creek Flood Control Project as a hazard response using Risa Palm’s integrative framework demonstrates the utility of this framework for understanding a real-world situation with all of its complicating factors. Elements at the micro, meso, and macro levels and the environment producing the hazard influenced the project, not only directly but also indirectly through linkages with other elements. For example, the macro-level environmental movement influenced the micro-level residents who influenced the meso-level city staff and flood control committee to produce an environmentally friendly plan (Figure 4). The large number of linkages between elements and the constraints accompanying each element created communication and procedural difficulties throughout the project. These identified difficulties can be addressed in the future to improve the efficiency of the response. Meso-level elements and in particular individuals acting in meso-level roles significantly affected the flood control project. Based on the experience of the San Pedro Creek Flood Control Project as a hazard response, Palm’s framework should be modified to explicitly identify the significant influence of a micro-level individual acting in a meso-level role on the meso-level element they represent.
The flood hazard in the Linda Mar neighborhood in Pacifica, California exists along San Pedro Creek, a perennial stream in a watershed with steep hills draining into a
Kelsey McDonald - Thesis 132short valley before emptying into the Pacific Ocean. Human alterations of the watershed increased the flood hazard over time, most recently by developing the area into a suburban community with a high percentage of impermeable surfaces and modified drainage network (e.g. culverts). These alternations increased the potential for flooding downstream by decreasing the lag time for the heavy rainfalls and increasing the peak runoff. All of these factors contributed to major flooding in Linda Mar in 1962, 1972, and 1982.
Many different elements at all levels influenced the response to the flood hazard along San Pedro Creek (Figures 2-4). After each major flood residents (micro-level elements) responded by calling on the city council and/or city staff (meso-level elements) to fix the problem, after which the city council initiated a flood control project. By evaluating how the meso-level objectives of the flood control project changed over time, many other elements influencing the flood control project quickly became evident. The proposed solutions to the flooding problem began in 1962 with the standard objectives to move water out of the area as quickly as possible, using channelization and other drainage methods. As the environmental movement (macrolevel element) progressed in the 1960s and 1970s micro-level residents began calling for the meso-level city council and city staff to both preserve San Pedro Creek and to provide flood control. The macro-level environmental movement also influenced federal and state policies (meso-level elements) that by requiring environmental protection also placed constraints on new flood control projects, making it less feasible
Kelsey McDonald - Thesis 133to use standard structural flood control methods, such as placing a creek in a concrete channel. However, the city council’s stated objectives for the flood control committee after the 1982 flood still focused solely on providing flood control and the means to fund it, making no mention of protecting the creek and the environment. At the same time environmental protection measures significantly limited the standard methods available for flood control and the means to fund them. Officials slowly began to adopt new approaches to flood control originating with Geographer Gilbert White. For the San Pedro Creek Flood Control Project, Scott Holmes, a micro-level individual working in a meso-level context, pioneered the idea of using environmental restoration as part of the flood control solution, and the final objectives of the flood control project from the city’s perspective became not only flood control but also environmental restoration.
A particular strength of Palm’s framework lies in establishing the linkages between elements to present a more comprehensive picture of the influences on the flood control project (Figures 2-4). For example, Scott Holmes, the meso-level city representative, is often credited with developing and implementing the approved flood control plan. However, the integrative framework points to many influences and constraints on Holmes when he developed the new Marsh Diversion Plan (or Wetland Bypass Plan), including the environmental movement (macro-level influence) and environmentalists (meso- and micro-level elements), regulations at the USFWS and CDFG (meso-level elements), available sources of funding (meso-level elements), open land adjacent to the creek (although land was not immediately available from Caltrans, a