2 minute read
Reconstructed Watershed Landscape
storm water. In time, the plant material will take hold and fill in the slope so that the netting is no longer visible. Volunteer native species of plants from the adjoining undisturbed slopes will invade in the process of natural succession to further repair and reduce slope erosion. Assuming all goes according to plan, visitors hiking along the trail will see in as few as 10 years a naturalized landscape, unaware of the steps taken to get from heavily eroded bare slopes to recovery with native plant cover.
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The Netherlands has had to devise increasingly robust and sophisticated strategies to protect the country from winter storms and flooding since as long ago as AD 800. The Dutch are known for their system of levees, canals, pumping systems, including windmills, and other approaches to ward against winter-borne flooding. Much of the coast perimeter of the country is protected against storm flooding with the creation of sand dunes constructed over earthen levees. The dunes have been planted with a variety of plant species, mostly grasses, as shown in Figure 5.31. The dunes appear to be natural but are in fact a cultural artifact and are appreciated as any native landscape feature. The plants and wildlife that inhabit the dunes have naturalized and, like any ecosystem, change and shift in composition over time.
Figure 5.31 Storm protection sand dunes, the Netherlands
Designed by the landscape architecture firm of Sites Southwest of Albuquerque, New Mexico, in collaboration with Bohannan-Huston hydrologic engineers (Figure 5.32), this project is an example of a community-scale landscape watershed reclamation and water harvesting strategy. The aim of the project is to collect and detain rainwater, allowing time for it to percolate through the soil to the underground aquifer. In the process of constructing an adjacent sub-division, massive amounts of earth moving was necessary. The landscape architects devised a restoration plan, selecting native plant species to restore the disturbed areas, essentially recreating the natural habitat and biodiversity of flora and fauna. Storm water carrying pollutants drains from the adjacent residential properties and streets and then flows through the reconstructed watershed. In the process, the runoff water is cleaned of most pollutants as the water moves across the vegetated landscape. The water eventually is directed to an impoundment basin, lined with stone-clad banks in a formal
circular pattern with paths, and seating areas above. A large sculptural element was installed as a landmark that provides a way-finding function for trail users. The project functions as an integrated experience in which one can appreciate the rich visual attributes of a high desert landscape and interpret the movement of storm waters within the natural and built watershed environment.
London 2012 Olympic Park, London, UK
LDA Design, United Kingdom, and Hargreaves Associates, USA, collaborated in the final design Figure 5.32 High desert water harvester, Albuquerque, New for the 2012 Olympic Park in London, UK (Figure Mexico. 5.33). The site selected for the Olympic Park was a previously contaminated industrial urban landscape. The design provides both new wildlife habitats and significant flood protection for East London. A tributary stream flowed through the site among discarded debris and carried a heavy load of toxic pollutants. In addition to having been selected for the 2012 Olympic
Figure 5.33 London 2012 Olympic Park, London, UK. Courtesy of Hargreaves Associates/LDA.
