What To Do With The World's Water
Water. Few single words carry such significance. As the most basic necessity for life on this planet, the importance of water can never be overstated. In light of current global circumstances, water and the host of issues associated with it have never been more relevant.
Climate change, population growth, urbanization, aging infrastructure and ecological degradation are placing convergent pressures on the planet's water supplies that manifest in three major challenges: water resource scarcity, the threat of flood, and the poor condition of many of the world's most productive ecosystems.
It is a situation as urgent as it is complex. By 2050, India's population, already experiencing intense strain on water supplies, is expected to begin running out of water, having reached nearly 1.7 billion people. Hurricane Katrina and the more recent Typhoon Ketsana, which struck DaNang, have exposed the vulnerability of coastal areas to catastrophic destruction. Yet more than 10 percent of the world's population is living in low-lying coastal areas. Globally, 70 percent of fresh water is used for agricultural irrigation, where it typically flushes pollutants and then is allowed to run off into ecosystems rather than being captured for treatment or reuse.
Cities meanwhile pollute water with raw industrial waste and spend billions on infrastructure that mixes stormwater with wastewater and pipes it out of the metropolitan area. By importing the majority of their water supplies from great distances, cities add to infrastructure and energy costs as well as environmental concerns.
Although these issues are currently more acute in drier or tropical climates, they will soon become unavoidable global phenomena.
We are looking at a vast, interconnected challenge, one that requires systemic thinking across geographies and across the boundary between natural and built environments. Interdisciplinary responses to the issues surrounding water are yielding some encouraging results. From the US West Coast, to China, Southeast Asia, and Australia, AECOM project work is advancing best practices in water resource management, aquatic ecosystem protection and enhancement, water sensitive urban design, and coastal flood protection.
Water resource management
Water supply reliability is made difficult by a combination of increasing population size, increasing urbanization, and the settling of population in areas with insufficient natural water supplies. Urban environments tend to disrupt the recharge of water resources that occurs in a natural hydrological cycle, widening the gap between water supply and water demand. When people do not live close to their water source, complex systems are required to store and convey water in an energy intensive manner, or expensive technologies such as desalination come into play. These solutions are not necessarily affordable in developing countries or sanctioned by the more stringent environmental regulations of developed countries.
"Effective water resources planning requires an optimum balance between demand-side management and supply-side solutions, pushing conservation and recycling to the maximum feasible level, and reducing system-wide losses," says David Blau, senior vice president and global water leader at Design + Planning at AECOM. This can only be achieved by a holistic approach that begins at the source and seeks to minimize impacts on the natural water cycle. Land use planning based on a catchment's carrying capacity, total water recycling, and designs that reduce changes to the hydrology of a watershed are key components of effective water resources planning.
Municipalities must develop long-term plans and strategies that emphasize flexibility in water sourcing and do not rely on a single source. There must be efforts to balance population growth and water usage increase with availability. Water conservation measures should be encouraged and enforced through appropriate pricing. Land use should be projected to match water availability over the long run, taking into consideration risk factors such as impacts from climate change. No longer can we adjust to current downstream issues; municipalities should look at their water needs holistically, balancing technical and socio-environmental considerations.
From the US to China, AECOM has helped governments adopt holistic, long-term approaches to managing their water resources. The Water Supply Management Program for San Francisco's East Bay Municipal Utility District extends water resources planning to 2040. This work includes evaluating the district's water conservation and water recycling programs; updating the land-use based water demands study; assessing the district's drought planning sequence; developing potential groundwater storage and recovery programs; integrating water supply connections; and emphasizing the security of aqueducts that cross the Sacramento-San Joaquin Delta. Especially under consideration are the impacts of global climate change on the district's water supply and demand.
The Flood Decision Support System for the Ministry of Water Resources produced a nationwide strategy for China to manage its water resources, building reliability of supplies while reducing the threat of flood. The report addressed China's six major river basins with a detailed pilot plan for the Huai River.
Beijing faces a water crisis affecting the quality of ground and surface water as well as accessibility to clean freshwater resources. Stormwater provides a potential source of freshwater for the city. AECOM developed a feasibility study, planning framework, and demonstration project for the Beijing Urban Stormwater Runoff Management System, funded by the United States Trade and Development Agency (USTDA) and Beijing Water Authority (BWA). The team used GIS and a computer hydrological model to monitor and predict rainfall volume in the Beijing metropolitan area. The project included a prototype facility for the Yizhuang District to test and to verify the system's preliminary design as well as stormwater wetlands, swales, and detention facilities to demonstrate green approaches to stormwater management and treatment.
Aquatic ecosystem protection + enhancement
The use of water for cities and agriculture is a complex relationship between the human and natural worlds. For this relationship to be a productive and a sustainable one, we must protect the health of the natural environments from which we draw water, remembering that fish need water as much as farms and cities. "Aquatic ecosystems are being degraded worldwide, and fish species are increasingly becoming endangered and threatened," says Phil Dunn, vice president of water resources and environmental compliance at Design + Planning at AECOM.
The Bay Delta Conservation Plan for the California Department of Water Resources is one of the most complex and controversial water management projects undertaken to date in California. It involves restoring more than 15,000 acres of aquatic habitat to support populations of at-risk Delta fish, including delta smelt; installing a new water conveyance canal to increase water supply reliability to more than 25 million California residents; and implementing actions to reduce the effect of pollution, invasive species, predators, fish entrainment, habitat reductions, and other stressors adversely affecting these at-risk fish species. AECOM is one of three firms leading the complex environmental studies that must balance a huge infrastructure project with the needs of the Delta's rapidly declining ecosystem.
AECOM is one of two major firms completing the environmental impact statement and environmental impact report for the San Joaquin River Restoration Project, an ambitious program to reintroduce a sustainable Chinook salmon population in a river that runs dry from agricultural diversions for much of its length. On October 1, 2009, interim flows were released, an important milestone in the re-watering of the San Joaquin below Friant Dam and the reintroduction of Chinook Salmon. AECOM has also played a crucial role in the San Francisco South Bay Salt Ponds Restoration, the largest ecological restoration of its kind on the US west coast. Returning commercial salt ponds to a mix of tidal wetlands and managed ponds, this project will provide wildlife habitat, flood protection, public amenities, and natural polishing of water entering the bay.
Aquatic ecosystem restoration in Asia has included the Fengchenggang Marine Mangrove Park in China. With funds from the United Nations Development Program's (UNDP) Global Environmental Facility (GEF), AECOM was appointed to plan one of the largest mangrove parks in China. The site, an existing 334-hectare mangrove forest, is a GEF demonstration site for the development of appropriate cross-sector sustainable management programs. The model mangrove reserve will serve as a center for training, research, and international cooperation.
Together with China's State Forestry Administration (SFA), AECOM published the first public/private collaborative research book focusing on wetland restoration. The bilingual handbook provides an easy to use reference for those involved in wetland restoration and management, drawing on international best practices and local knowledge and expertise. AECOM's relationship with SFA is ongoing, and we are currently collaborating to develop national certification guidelines for China's wetland parks.
Water sensitive urban design
Contemporary cities disrupt the natural hydrological cycle. As a result, infrastructure must be built and maintained to serve water treatment and conveyance needs. Cities now face the challenge of retro-fitting existing infrastructure, something which is costly and complex due to conflict with other site utilities already in place. "Water sensitivity is the notion that a city, both through its built environment and its collective knowledge and behavior, can become part of the natural hydrological cycle," says Tony Wong, principal of ecological engineering at Design + Planning at AECOM. "This is achieved by the creation of green infrastructure, which naturally helps to conserve potable water, manage stormwater, and reduce wastewater."
Education, water pricing, and regulatory ordinances are tools that cities use to enforce wise use of water. Water recycling is mandated in many cities to build water sensitivity. Encouraging ecological restoration projects within cities as multi-purpose facilities is crucial. These efforts rely upon social and political capital, which is built by publicizing innovation in built projects. Singapore is successfully selling NEWater, which is drinking water regenerated from treated wastewater using the latest membrane technology. The public success of this type of measure is essential for an island that relies on Malaysia's pipeline for 1/3 of its water, and therefore the city is working very hard to increase its water self-sufficiency.
AECOM is helping Singapore reach water sensitivity by providing consulting on green infrastructure development as part of the ambitious Singapore Sports Hub project. Applying WSUD principles, this green infrastructure project aims to attain greenmark accreditation (equivalent to LEED® in the USA) by collecting stormwater falling on the complex and naturally polish and convey the water for subsequent reuse.
AECOM's other completed projects include the Docklands Park Wetland, a piece of natural infrastructure that harnesses stormwater from a largely urban catchment as an alternative source of water for non-potable use throughout the City of Melbourne in Australia. The Shanghai Chemical Industrial Park created a natural treatment facility that is cleansing industrially polluted water while serving as a piece of green public realm in China. AECOM has produced the Water Sensitive Urban Design Handbook (PDF) to showcase the innovative techniques used in these and other projects.
Taking these concepts to their full potential, an AECOM team won The History Channel's City of the Future competition by proposing a scenario in which Atlanta would solve its dual problems of aging water infrastructure and drought. The city would become a city in the forest, using natural wetlands to capture and convey stormwater as a restorative rather than an engineered solution. Clustering development around transit routes that followed the higher ground would create vibrant, efficient densities alongside pristine and productive natural habitat.
The potential of stormwater as a resource and the proposition of cities as water catchments is a focus of AECOM research collaboration with major Universities in Australia, integrating the design of future cityscapes and built form with ecological elements that harvest and treat stormwater for non-potable use. The Facility for Advancing Water Biofiltration, a research venture between Monash University and AECOM, successfully provided scientific proof of concept for biofiltration systems and is furthering industry-wide adoption and implementation of the technology through its integrated research projects. This collaboration, linking research to practice, is now expanding to examine the potential for green infrastructure to influence urban micro-climate at a range of scale, from buildings to neighborhoods, as well as the socioeconomics of delivering sustainable neighborhoods around the concept of urban metabolism and industrial ecology, and new urban water governance models for advancing water sensitive cities.
Coastal flood protection
While obtaining water is oftentimes the challenge, sometimes water itself is the danger. In an age of climate change, catastrophic coastal storms demand a new approach to coastal development. We must plan and design development projects that minimize building in flood-prone areas surrounded by substandard levees and seawalls. The obstacles that stand in the way include old ideas about coastal development, not fully embracing and understanding the implications of sea level rise, and the increased real estate value of coastal properties.
"It is safe to assume that the storm track may change as part of climate change phenomena, meaning that areas normally unaffected by typhoons in the Pacific or hurricanes in the Atlantic may start to be impacted," says Stephane Asselin, vice president and global director of the environmental + ecological planning practice at Design + Planning at AECOM. "Also, the frequency and intensity of damaging storms may increase. Given what we know about the recent devastation that coastal storms can cause, we should avoid developing in areas that put ourselves at risk. We must also enhance the flood buffering function of coastal wetlands. For currently populated coastal areas, an advanced and effective flood forecasting and warning system will be crucial to minimizing loss of lives and properties."
In designing a coastal resort in DaNang, Vietnam, AECOM, via review of coastal geomorphology and historical storm surge data, advised the client to adopt appropriate coastal setbacks for the development taking advantage of the natural protection that historically protected the site from severe storms.
From riverbed to city street
From the health of the aquatic ecosystem, to the municipality's need for a reliable water supply, to a city's water sensitivity, to a coastline's resilience to sea level rise, AECOM addresses the full spectrum of water-related planning, design and ecology issues. Through our technical expertise in water infrastructure, AECOM adds an adjacent segment to this expertise. Thus water, as one of the world's dominant issues, is an example of how our interconnected, global consultancy has the capability to address the complex challenges of our time.
Jake Herson