Environmental Restoration

The river waterfront in Bilbao, Spain, shown in Figure 6.29A was not previously accessible to the public as the river was considered a working river used for shipping and lined with warehouses and industries. With the construction of the Guggenheim Museum at the water’s edge, the city began a cultural rebirth, as part of a larger process in the city’s ambition to reinvent itself as a tourist attraction and more diversified economy. The boat mooring and warehousing functions were replaced by a continuous park and promenade connecting new visitor venues such as the Guggenheim Museum, residential living, and commercial establishments. Dramatic and extensive outdoor lighting extended the use of the river edge into the evening. Just about any city with a river flowing through it has traditionally turned its back to the river for recreation and cultural functions. The tide, so to speak, has turned and as the remnants of the industrial revolution have outlived their economic usefulness, cities now foresee new economic and social advantages by making their water edges more attractive and increasing the livability and health of the city. The Paseo de Santa Lucia River walk in Monterrey, Mexico, is a 1.6 mile (2.3 km) reconstructed drainage canal connecting the central downtown to a park and entertainment venue in what was previously an industrial steel mill plant (Figure 6.29B).

The water body in Figure 6.30 was once a nearly invisible flow of water buried in the urban fabric of a densely populated historical neighborhood in Beijing. The neighborhood was supplanted with the construction of the Beijing 2008 Summer Olympic venue. As part of the planning and design of the project, the river was restored with a park-like greenway, complete with reconstructed wetlands. Trails were constructed along the greenway and, as can be seen in Figure 6.30, a boardwalk and viewing platform were included in the design to allow public access to the water’s edge. The plant species for the wetlands along the river edge were selected to perform a water cleansing function as well as wildlife habitat.

Buffalo Bayou in Houston, Texas, (see Figure 5.27 on p. 105) is another example of a nearly forgotten watercourse that for years was considered an eyesore and a threat to adjacent neighborhoods due to flooding during periodic heavy rains and storms. The City of Houston, like so many urban areas, had turned its back to the water’s edge, not seeing the multiple advantages of visual and

Figure 6.29 A: Bilbao waterfront promenade, Bilbao, Spain; B: Paseo de Santa Lucia walk, Monterrey, Mexico, by Enrique Albarroa, landscape architect.

Figure 6.30 Beijing 2008 Olympic Park waterfront and river restoration, Beijing, China.

physical access by including a continuous parkway and trail system along its waterway corridors. The redesign of Buffalo Bayou was originally conceived as a flood control project. The design included increasing the floodwater-holding capacity (detention) of the waterway by widening the bayou. In addition, physical obstructions were removed to enhance the water flow. The city took the opportunity of re-envisioning Buffalo Bayou as a park-like corridor. The added benefit of this approach accommodated the addition of pedestrian walks, ramps, and bridges that increased visitor access from adjacent neighborhoods. A continuous trail system was also built with pocket parks spotted along the greenway to further serve the outdoor recreation needs of an increasing urban population.

Low impact design (LID) and other storm-water management design initiatives are covered in Chapter 5. Traditionally public works departments have constructed and managed extensive systems to gather and transport (essentially a system to get rid of) storm water or rainwater through underground pipes to a water treatment plant or directly into rivers and wetlands. The possibility that this water could have beneficial use was not appreciated, given what was considered a cheap, almost inexhaustible resource. Today, with growing numbers of urban and regional areas experiencing water shortages, we are slowly coming to realize the benefits and opportunities of conserving storm-water runoff by basically devising ways of keeping it on site rather than disposing of it. Shown in Figure 6.31 is a project where a city utility rethought how to better manage storm water and hired a landscape architecture firm to design a series of landscape interventions to retain surface water on site. This was accomplished by the elimination of area catch basins and redesigning the street curb and gutter system. In Figure 6.31A is a newly constructed rain garden in what was a previously paved surface with area catch basins. The area was re-graded and repurposed as an outdoor garden for employee use during lunch or for holding community events. Rainwater is directed to the rain gardens that were first prepared with a series of depressions for detaining water. The detained water is allowed to percolate to the subsurface to recharge the natural underground water aquifer. The photograph in Figure 6.31B shows bioswales constructed between the sidewalk and the street. Breaks in the concrete curb were made to enable water to flow into the bio-swale or to an Figure 6.31 Burbank, California, utility campus: A: Rain garden; overflow area in the background. The water then B: Bio-swale in central interior space, by Ahbé Landscape percolates into the soil to replenish the ground Architects. water below.

The Netherlands, a country with a long history of comprehensive storm-water management, has A applied low impact design and best management practices throughout the country (in both urban and rural areas). The use of a modular pavement system reduces the unsightly disruption of tearing out street and sidewalk pavement for maintenance repairs of underground infrastructure such as potable water and electricity distribution lines. The modular pavement is easily replaced with little evidence of the repairs, such as the ubiquitous patchwork of pavement repairs that are visible on American roads, paved areas, and walkways.

The circulation corridor through the Delft Technical University is shown in Figure 6.32A. Three distinct traffic lanes exist side by side serving motor vehicles, bicycles, and pedestrian traffic. The surface material used for all three is either modular units or porous material allowing rainwater to penetrate to the subsoil below. The use of modular pavement in a residential neighborhood, also located in the Netherlands, is shown in Figure 6.32B. Water is allowed to penetrate the different modular surfaces rather than be carried off to be disposed off-site.

Crissy Field, a former airfield serving the his- B toric U.S. Army Presidio,5 is now part of the Golden Gate National Recreation Area in San Francisco, California. The scene in Figure 6.33 is of the restored bay wetlands and wildlife habitat accessible from a popular public park, both designed by Hargreaves Associates, landscape architects. The wetlands were restored using native estuarine and upland plants accessible by raised boardwalks. The location has spectacular views of the Golden Gate Bridge and the San Francisco skyline with the backdrop of the surrounding coastal mountain range. Many of the native plants were planted by organized school groups, families and other citizens in the area as Figure 6.32 A: Pedestrian and vehicle corridor, Delft Technical part of a public education component of the project. University, the Netherlands; B: The use of modular pavement

Landscape architects in China have led teams materials in a Dutch residential neighborhood. consisting of other professionals and scientists designing a large number of urban river and wetland restoration projects as part of a government initiative to increase the health of these water-based landscapes and to improve the livability of the surrounding communities. Qunil National Urban Wetland Park in Harbin and the Houtan River Wetland Park in Shanghai, designed by Turenscape (Figure 6.34), garnered ASLA design awards. The urban wetland parks were created as a solution to manage storm water and serve to filter the runoff and improve the water quality and restore the biodiversity of the wetlands. The following narrative of design objectives is part of the project description by Turenscape:

Figure 6.33 Crissy Field Wetland Restoration at the Presidio in San Francisco, by Hargreaves Associates.

Figure 6.34 A: Qunil National Urban Wetland Park in Harbin; B: Houtan River Wetland Park in Shanghai, both projects designed by Turenscape, China. The initial understanding of the site was to turn the isolated wetland into a major park as well as a storm-water and wastewater remediation area that would enhance native wetland habitat. But thorny issues emerged as the result of further study. The landscape architect discovered that the seasonal change of the water table is as much as 2 meters (6.6 feet) between dry and wet seasons, which thwarts the intention to combine public [recreation] spaces with a resilient wetland landscape. In addition, such a large public space would be difficult to manage since the restored native vegetation would soon become too messy and wild to allow access and be used by the people year round.

The design objective was to fashion a waterresilient wetland park, which functions as an integral ecological infrastructure that remediates storm-water and waste tail water from the water plant. In the process, the wastewater could rejuvenate the wetland habitat. Furthermore, the landscape architects determined that limited design interventions would best serve the project objectives and transform the wetland into an accessible public space.6

Environmental impact engineer was the title the oil company consortium responsible for the design and construction of the Trans-Alaskan Oil Pipeline gave to the team of landscape architects they hired. The team of landscape architects assisted in developing landscape and wildlife habitat restoration plans for the 860+mile-long (1385 km) pipeline right-of-way through diverse ecosystems beginning in the North at Prudhoe Bay to the southern terminus at the Port of Valdez. Figure 6.35 captures the result of the restoration activities showing the eventual dominance of native willow and other woody and perennial plant species. The efforts of the landscape architects included planning and executing a series of test plots planted with field-collected native material; collecting, storing, and later overseeing the planting of willow hardwood cutting; collecting seeds of several tree species that were provided to contract growers, then planted in selected areas; and overseeing the collection of field-collected woody species that were planted in sites disturbed during the construction of the pipeline. This was a nearly three-year project that initially began in response to federal and state environmental impact regulations, resulting in the program of restoring native vegetative cover within construction areas along the pipeline right-of-way, including gravel borrow sites, access roads, storage areas, and construction camps.

Figure 6.35 Construction restoration with native vegetation, Trans-Alaskan Oil Pipeline, by Bruce Sharky, project landscape architect.

Figure 6.36 Irvine residential community, by SWA Group. Figure 6.37 High-rise residential community, Hangzhou, China.