Many of us in the environmental field have been talking about how we are running out of freshwater, how we're in a time of peak water and how we're headed into a water crisis. With good management strategies and solutions from both engineering and economics, we can avoid a crisis and achieve water security.
For those who don’t think much about freshwater, running out of water might seem like a ridiculous idea considering how much water there is on Earth. The reality is, the water we have access to – less than 1 percent of the 3 percent that is non-saline - is limited, and our access is changing. Climate change models indicate that how, where and when that precipitation falls will change already is changing from historic averages. The problem for us is that we have built fixed infrastructure around a specific set of conditions where we rely on slow melting of snow packs, the ability to catch and store rain during specific times of the year and regular groundwater extraction and replenishment to meet all of our needs.
Now, we see reduced snow packs, melting glaciers, droughts and heavy rains with unpredictable timing. Combine that with the poor water management strategies, ongoing extraction of groundwater faster than it can be replenished and continual and ever-changing man-made activities that pollute water sources, and our water security is threatened.
We have hard choices to make as the United States' population is on track to soar past the 400 million mark (PDF) by 2050. We need integrated strategies for growth, agriculture and industry to ensure that all our water needs will be met. There aren’t really new water sources to be bought, sold or tapped. What we have is what we have. Today’s water managers are evaluating water portfolios against projected populations and budgets at all levels, from local to multi-state and international.
Options for municipal supply management include increasing capacity through alternative sources such as desalination of sea water or moving large amounts of water over long distances, but these options are expensive, energy intensive and, in some cases, impossible. They don’t make sense environmentally or economically. As cities and towns begin meeting growth projections, permanent capacity increases won’t always be a possibility. Beyond savings achieved through conservation and efficiency – which should be everyone’s top priority – water managers will need to find new ways to meet upcoming needs and improve management without sacrificing the environment in the process.
One option on the demand side that is being used more frequently, especially in the arid American west, is the dual allocation water supply system. Dual allocation allows for the use of reclaimed wastewater to meet non-potable water needs and distributes fully-treated, potable water only where it is needed and required. This can significantly reduce treatment requirements and expanded capacity requirements in times of water shortages. No new technology is needed to accommodate a dual allocation system. All that’s required is a second set of pipes. While retrofitting existing systems may be more of a cost burden than some communities want to bear, planners and water managers should consider the cost effective measure of requiring dual allocation systems for future construction and remodeling of existing systems. Homeowners also should consider designing such systems into their new and remodeled construction and requesting that their communities require such designs.
On the supply side, where increasing capacity through purchase of new water rights is not possible, water supply managers will need to diversify their portfolios. Consideration should be given to the inclusion of leases and options as a way of reducing risk and vulnerability to droughts and reducing cost volatility. Short-term leases allow communities to cover shortfalls without having to assume the costs associated with acquiring new water rights, then building and maintaining new treatment capacity for water that may not be used most of the time. Options allow water managers and planners to lease water at lower prices for use at a later time, if needed, when higher demand could drive up prices. Both options allow greater flexibility and reduced risk.
Although we face an uncertain future where water is concerned, with creative thinking and flexibility we will meet our needs, even in the face of shifting precipitation patterns and increasing populations. Keeping our water supplies safe, available and in public control should be a high priority for us all. When community members and water managers work together large strides towards water security and independence can be achieved.