In Deep Water: How technology can localise and restore urban water infrastructure
5 August 2013, source edie newsroom
Unfortunately, many cities have been heading in the wrong direction when it comes to their water infrastructure. Figures show that 493 million people in cities today share their sanitation facilities.
In 1990 this number was 259 million, whilst over 80% of wastewater worldwide is not collected or treated, and urban settlements are the main source of pollution. Alongside this, water use has been growing at more than twice the rate of population increase in the last century.
If you'll forgive the pun, many parts of the western world have put themselves "in deep water" by simultaneously centralising water systems while underinvesting in water infrastructure. We're then surprised when the inevitable rationing, flooding, or sewage overflows occur (in the UK, 3.3 billion litres of water were lost through leaking pipes every single day in 2010 - that's 130 litres per person).
To reverse these trends, we need to focus on localising urban water systems and restoring water infrastructure, both of which can be accomplished with today's technologies but requires a change in policy and mindset.
Due to the high cost - economically and environmentally - of transporting and treating water, local governments and water utilities should "seek out every drop on hand before looking afield," reusing and recycling water to the greatest extent possible. Before transporting water from one state or city to the next, they could consider conservation policies, leak repairs, and water recycling.
In lieu of dams or desalination plants, they could evaluate alternatives to water for cooling or fracking. Instead of discharging stormwater or black-water from a site for treatment by utilities - requiring huge networks of expensive sewage and sanitary pipes and pump stations - property owners could reuse it onsite for irrigation and other non-potable water needs. In all of these cases, localising the water system allows for better service and reliability with lower infrastructure cost.
Why are we underinvesting in water infrastructure? In part, government austerity measures view water infrastructure as a painless area to cut. The US government's proposed 37% cut to the Clean Water and Drinking Water State Revolving Funds for 2013 punctuates a steady decline of federal support for water infrastructure projects since the Clean Water Act of 1972. This year, these low-interest loan programmes will cover only 2% of the estimated $98bn needed.
Meanwhile, private investors hesitate to back centralised water supply and sewage projects because of their high costs, vulnerability to droughts and energy security risks. And ratepayers who enjoy cheap water and rarely consider the pipes behind their bathroom wall see no reason to pay more.
Similarly in the UK, last year it was revealed that water companies could save more than £1bn if the problem of cyclical investment in the sector was properly addressed according to government findings. The study, published by Infrastructure UK with the support of the water industry and regulator Ofwat, estimates that companies could achieve efficiency savings of between 3% and 5%, equating to between £600m and £1.1bn every five years. It also estimates that the loss of productivity caused by cyclicality adds an extra £5 to £6.50 on to customer's annual water bills and approximately 40,000 jobs could be saved.
To localise an urban water system, one must first gain a comprehensive understanding of the watershed surrounding the city and the ability to design and analyse new possibilities in context. That involves unifying data on existing conditions and analysing designs, as these groups have done.
To make the most of locally available water, Scotland's Roseisle Distillery houses a water reclamation plant that treats whisky's liquid byproducts for use in the malting process, saving up to 300,000 cubic meters of water per year.
In the US, to preserve Fairfax County's freshwater supplies, Dewberry installed 5 miles of purple pipe to deliver treated wastewater to nearby parks for irrigation and a local waste-to-energy facility for cooling purposes.
Also on the other side of the pond, to protect local stream ecosystems, Washington based Clark County Public Works added 15 rain gardens in a subdivision with undersized stormwater facilities. These biomimetic design features absorbed and filtered polluted runoff that would have otherwise discharged into the surface waters.
To restore water infrastructure, one needs to attract long-term capital at good rates, which requires confidence on the part of government, willingness-to-pay by ratepayers, and a return on investment for private investors.
To complete the environmental permitting process for a client's new development in Virginia, US, Timmons Group restored the affected waterways and habitats for local flora and fauna. In addition to the environmental benefits, the client's decision to invest in natural infrastructure reduced costs by over 50% by eliminating the need to purchase mitigation bank credits.
What these projects exemplify is how creative application of today's technology - and often a healthy dose of political will - can help to solve many of the water problems we're currently facing, with lasting positive impacts on the local environment and economy.
Water considerations need to be a key part in infrastructure and construction decision-making and the technology and building materials needed to help make these decisions are more readily available than ever before. It's time to stop making excuses and follow the examples of some of the organisations mentioned here - we all have a role to play.
Brian Young is Autodesk's Sustainable Infrastructure Program Manager and Emma Stewart, Ph.D. is Autodesk' Head of Sustainability Solutions and a faculty member at UC Berkeley
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