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Commercial Site Jiffy Lube and Convenience Commercial Area at Pico Boulevard and 24th Street, Santa Monica, CA
TEAM MEMBERS
Landscape Architecture Graduate Students:
PROTOTYPE This is a typical commercial site, with 1-story buildings and paved parking areas facing a main arterial street. Over 90% of the site area is pavement and roof surface. SITE PROFILE The commercial site is located on Pico Boulevard, a major east-west arterial. The project area includes two separate parcels and extends the full width of the block between 24th Street and Cloverfield Boulevard in Santa Monica, a middle- to upper-income city in Los Angeles County. The site includes a convenience commercial building with three small businesses and, on the adjacent parcel, a Jiffy Lube automotive oil-changing service. Commercial buildings line Pico Boulevard, but the neighborhood around this heavily developed commercial area consists of well-maintained, single-family homes and several schools. The underlying soils on this site are of the Hanford association and are over 60 inches deep, well drained, and have moderately rapid subsoil permeability. In total, the charrette site is 24,133 square feet, or 0.55 acres. The Jiffy Lube parcel is 14,758 square feet with the building covering 24% of the site area and the parking lot covering 64%. A landscaped boulevard accounts for 12% of the Jiffy Lube parcel area. The convenience commercial parcel consists of approximately 9,375 square feet. The buildings cover 37% of the parcel, the parking lot has twenty-two stalls and covers 53%, while sidewalks and other paved areas (such as the rear driveway for deliveries and trash collection) cover 3%, and landscaping accounts for 7% of the total parcel area. An alley separates the convenience commercial property and the Jiffy Lube from the neighboring residences. In summary, 61% of the site is covered in pavement, 29% is covered by buildings, and 10% is planted with traditional landscape materials. SITE DESIGN PROPOSALS Taking advantage of the permeable subsoils on this site, the underlying strategy of the design and management proposals is as follows: to make the site surfaces more permeable in order to facilitate water infiltration and to enhance flood control; to reduce the requirement for irrigation water by installing drought-tolerant plants; to capture, store, and re-use the rain water that falls on the site as irrigation water; to capture and remove pollutants from the stormwater run off; to reduce energy consumption by decreasing the need for air-conditioning; and to maximize the use of trees and plant cover for aesthetic purposes, energy conservation, and to help reduce air and water pollution. Increasing Shade The commercial site design proposes a total of fifteen new shade trees for the site. These large trees are strategically located to shade buildings and pavement. Creeping fig vines are trained to grow on existing masonry walls and up the sides of the proposed stormwater storage tanks. The vine-covered walls help to cool the building interiors. The team provides arbors and trellises for the building walls as well as for above the patio areas near the entrances to the Jiffy Lube and the commercial building. The increased shade for parked cars reduces the amount of volatile organic compounds emitted by petroleum products in gasoline and in plastics around overheated vehicles. Increased tree cover and vegetation also helps to create a more inviting and comfortable environment for patrons. Underground Cisterns There are two existing underground storage tanks located at the Jiffy Lube site. The tanks have a total capacity of 15,000 gallons. They are presently used to intercept possible petroleum-based chemical spills. These tanks could easily be adapted to hold rain water that could later be used for site irrigation. When full, these tanks overflow into the existing municipal storm drainage system. On the hundreds of other similarly equipped car-oriented commercial sites located in the Los Angeles River watershed, tanks like these could be adapted to release stored rain water in the event of a flood warning. With the release of the water already stored in the tank, additional storage space would be freed up to intercept 15,000 gallons of stormwater per site, on average, during a flood emergency. Roof Water Cisterns At the Jiffy Lube, a portion of the roof run off will be diverted into an existing raised planter located in the alley. It will be converted to catch and temporarily retain 800 cubic feet of rain water. Roof run off from the convenience commercial building will be directed through modified down-spouts into large concrete holding tanks located at the 24th Street entrance to the parking lot and in front of the building. The tanks are made of used concrete pipes salvaged through the CalMax Program and are designed to hold over 100% of projected flood period roof run off. This water will be stored and used for drip irrigation during the dry season. Regrading and Infiltration The grades in the enlarged planted areas that are located inside the property line at the city sidewalk along the frontage of both parcels have been lowered to accept stormwater run off from the site's paved areas. The team proposes drainage flow deflectors and minor regrading of paved areas, where necessary, in order to direct water into the enlarged planting beds. On the convenience commercial portion of the site, the team provides a constructed dry stream bed in the planter areas to slow surface drainage and to allow water to soak into the root-zone of the plants and into deep drainage chimneys. The drainage chimneys are vertical pipe stands that are filled with fast-draining rock and sand filter material. The filter material is installed at the inlet of the drainage chimneys and is inoculated with bio-remedial agents to help break down petroleum by-products and other pollutants carried by the stormwater. Off-Site Infiltration Zone The team included a permeable paved area at the south edge of 24th Street, directly under an existing parking space. This infiltration zone consists of four subsurface drainage chimneys covered with a permeable paved area. The permeable paved area filters the first-flush rain water and prevents it from clogging the chimneys. In the event of a flood, this system serves as an overflow for the recessed planters at the site property line. The infiltration zone will also accept stormwater from the street. This drainage structure can easily be built into other city streets, where soil conditions permit. Green Roofs The roof and sheathing has been removed from the area over the patio outside the meat market. This simple renovation will admit light into the building, improve air circulation, provide a place to grow vines, and create a more pleasant outdoor space for tables. Landscape Management The need to import water for irrigation has been eliminated through the installation of storm-water storage tanks and water conservation measures. Through the use of an efficient drip irrigation system controlled by a rain sensor, the water from the storage tanks will be used for irrigating the plant beds during the dry season. Irrigation requirements on the site will be reduced through the use of drought-tolerant plants arranged by hydrazone in swaled catchment planters that will directly receive available stormwater run off. Mulching and increased tree shade will greatly reduce evapo-transpiration rates from the soil and plants. Nutrients will be kept on the site by allowing plant litter to accumulate in the beds, rather than by the use of synthetic fertilizers. Also, plant varieties will be selected for their appropriate size and their ability to thrive without fertilization. SUMMARY The charrette team was able to achieve all of the performance thresholds using very cost-effective remodeling strategies. Without altering the use of the site or the number of parking spaces on either parcel, paved areas were reduced and stormwater was stored, re-used, and returned to the subsoil. The team proposed cleaning stormwater with such simple and cost-effective management practices as, re-using green waste as mulch for plant beds in order to hold irrigation water in the soil for longer periods of time. In addition, placing simple shading structures and vines on the existing buildings is very cost-effective and helps to create cooler and more attractive auto-oriented businesses. CONSTRUCTION BUDGET The charette team provided a construction budget for the proposed work, rounded in 1997 dollars, as follows: All proposed site improvements, planting, stormwater irrigation system, filter beds, subsurface infiltration areas = $70,000. Construction Contingencies (30%) = $20,000. TOTAL ESTIMATED COST OF CONSTRUCTION: $90,000. Note: Professional design fees for engineering and landscape architecture will be required (allow 20%) = $20,000. BENEFIT ANALYSIS The following benefit analysis provides a cost value per year; per 30-years; and a total value over thirty years for remediation of the entire property. This information was provided by the charrette team in 1997 dollars.
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