Parking Expansion DTF
Parking Expansion DTF
Parking Expansion Disappearing Task Force
- January 26, 2000
- 1:00 - 3:00 p.m.
Attending: Jill Cordner, Thad Curtz, Michel George, Doug Hitch, Thomas Holz, Steve Huntsberry, Sherry Parsons, Paul Przybylowicz, Darren Shaffer, Jim Stroh, Masao Sugiyama, John Carmichael
Jim Stroh made a presentation on the hydrology of Evergreen's parking lots. His presentation is summarized in a handout he distributed, which can be found at: http://www.evergreen.edu/user/parkingdtf99/stroh_notes.htm. Jim presented a watershed model intended to approximate the college parking lots. He compared the runoff associated with forest, asphalt, and grassy "meadow" similar to many of the landscape islands in the current parking lots. It is desirable to keep the peak discharge of runoff to a minimum. High peak discharges create erosion and scour stream beds. The ecology of streams is very sensitive to this kind of damage. Forest is, by far, the best cover in this respect. In Jim's model, which assumed 1.6 inches of rain in 24 hours, forest would produce no runoff. For a meadow, half of the rainfall would run off. All of the rainfall would run off from asphalt. Also, because asphalt would concentrate the rainfall very quickly, the peak discharge would be much higher. "There is no hydrologically ï¿½nice' way to add more conventional stalls at the expense of vegetation." More storm water drains and plumbing would only speed up the rate at which the rainfall is concentrated and make the peak discharges worse.
Jim responded to several questions from the DTF, including the following:
- Runoff from the parking lots has been scouring local streams for more than 20 years now. If we improve the runoff now, will the streams recover? Jim said that it would be interesting to see how the streams would respond.
- Do the storm water retention ponds commonly built along with new development help? Ponds built to current standards do not make a difference. They quickly reach capacity and become useless.
- Does it make a difference whether there are a few large green areas or many smaller green areas in the parking lots? Jim said that the quality of the green areas would be more important than their distribution.
- Currently the landscaped islands are above the level of the asphalt. Would it be better if the asphalt sloped toward the islands, which could be level with or below the asphalt? It would allow some water infiltration in small storm events, which would be desirable.
- The lots currently have forest at their edges. Should the asphalt be sloped to direct the runoff directly into the forest? The key would be to avoid exceeding the capacity of the forest to absorb water. Currently, the lots drain toward areas where the water table is already very high in the winter.
2. Alternative storm water management
Thomas Holz, from SCA engineering, talked about zero-impact alternatives for storm water management. In theory, if an impervious surface is sufficiently small and isolated, the soil around and even beneath the impervious surface could absorb the runoff, in which case runoff would not have to be piped to streams where it does considerable damage. Tom is currently working on a study with Michel George to assess the feasibility of such designs for campus structures. The report should be finished in three or four months. Several options are available. For buildings, roof gardens can curtail runoff. Buildings can be designed to collect and reuse the water that runs off the roof. (Michel said that this option is being considered for Seminar II.) For parking lots, Tom described a design in which pervious pavers are laid over a deep bed of crushed rock. If the conditions are right (the area is not too large and the surrounding area undisturbed), the layer of crushed rock can store storm water until it flows into and is absorbed by the surrounding area. Tom will give a talk on zero-impact storm water management on campus on February 7.
Tom responded to several questions from the DTF. Paul asked about the environmental impact of fluids leaking from cars in a pervious paving system. Tom said that it was hard to say what the impact would be. It is possible that the fluids would be trapped under the parking area and would be kept from streams, but they may present a long-term problem.
3. Commute Trip Reduction
Sherry reviewed the material on Commute Trip Reduction that she previously provided. She said that a successful program should include a variety of options and a combination of incentives and disincentives, including increased parking fees. Currently, the college has separate programs for students and faculty/staff. These programs should be combined. The free bus passes that students now receive will soon be extended to employees. The carpool benefits that staff receive should be extended to students. Sherry recommended that the college use the RCW that gives it the authority to collect a transportation fee from students, faculty and staff. The college should also consider implementing "preferred" parking areas, metered parking, etc. There are several policies the college could revise to encourage commute trip reduction: most importantly, class scheduling, but also telecommuting, flexible work schedules to facilitate ride sharing, and perhaps providing release time for long bus rides.
Doug was asked about the union's position on using parking fees to fund commute trip reduction efforts. Doug said that the union has a long history of defending the idea that parking fees should pay only for parking. He doubted that union members would be willing to abandon that principle. Thad suggested that parking fees might go up by the same amount whether the money is used to build additional parking spaces or to fund commute trip reduction programs that allow the college to avoid building those spaces. Doug said that a commute trip reduction program that put money in the pockets of employees might be worth discussing.
4. Other discussion
Darren presented a revision of the proposal he described last week. He estimates that it is possible to add 900 additional spaces in B and C lots without cutting any large trees.
Masao said he remains in favor of drawing a line and telling the county we are not willing to build more parking.
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- This page last updated on January 31, 2000.