Clean, safe, water delivery to your home is a really good idea.
Sanitary treatment of water waste from your home is a really good idea. Protecting valued assets from periodic destruction is a really good idea. These have always been good ideas but the Roman model of aqueducts languished for millennia. It is only in the past 50 to 100 years that engineering and technology have made these ideas affordable without the crushing costs of conquering neighboring nations to provide slaves for the task.
The construction of water infrastructure experienced a boom as modern engineers solved the problems of storing water for when it is needed, moving water to where it is needed, removing and treating water from where it is not needed and preventing water from going where it is not wanted. Those engineers did a really, really good job. They did not over-design. They did not presume that they could accurately predict what our needs will be – they designed for contemporary needs with comfortable safety margins.
Their designs have served us very well. There has been infrastructure expansion but little need for infrastructure renewal for at least two generations creating a ‘bust’ following the boom. We are now seeing the start of the ‘echo’.
The American Society of Civil Engineers (ASCE) report card quantifies the issue for the United States. There is no similar global report but one can reasonably assume a similar life cycle for global water assets.
The average age of 84,000 dams is 52 years with 14,000 dams listed as high–hazard.
There are 4,000 deficient dams, half of which are high-hazard. The cost to repair is $21B. There are 240,000 drinking water main breaks per year. The cost to replace is $1T. There are 100,000 miles of levees. Public safety is at risk. The cost to repair or replace is $100M. The total investment for water and wastewater renewal is estimated to be $3.6T
The state of Oklahoma is responding with a comprehensive water plan. Funding assistance for communities and rural water districts water and wastewater infrastructure renewal is $3.2B to date.
Largely in response to 2011 being the worst year-long drought in the state’s history, the state of Texas has just allocated $2B for the financing of priority projects for the state water plan.
Not long before the shutdown of US federal spending the ‘Water Resources Reform and Development Act of 2013’ was introduced to the House to finance port, inland waterway, drinking water and anti-erosion projects and speed up delivery times.
The US may not be a reliable index of the rate of infrastructure renewal globally but it is the only jurisdiction for which hard numbers are easy to come by.
Even allowing for a large margin for error, scaling of the cost of US renewal to the entire western world would result in a very large number. Add into this the cost of development of new water infrastructure in BRIC and other developing countries and the cost is staggering.
There is just one small problem: the need to design this entire water infrastructure to be reliable for another 50 to 100 years.
This design requires specifications and those specifications need to be informed by reliable data about the variability inherent in availability of water sources.
Design for the 21st century is, perhaps, a bit challenging.
In the 20th century a robust design only required a good estimate of central tendency and standard deviation of flow statistics. The hydrological cycle is accelerating. The extremes are becoming more extreme. Durations are becoming more enduring. The timing and frequency of cycles (seasonal, decadal) are changing. Environmental values attached to water often meet or exceed economic values for water use.
A different approach is needed for monitoring in the 21st century.
We are very good at collecting data to develop a robust estimate of the mean at a location. We are not so good at accurately characterizing variability. Network density needs to increase to characterize scaling factors and non-linear dependencies in the dispersion of flow statistics. Transference of information from long term gauges to ungauged basins will require new gauging at every scale of interest.
There needs to be a lot more data to provide the evidence for evidence-based decision making.
In the absence of adequate data, well informed decisions cannot be made. Misinformed decisions will inevitably lead to adverse consequences.
The US Geological Survey has recently published a gap analysis indicating that uncertainty in estimating useful flow statistics is greatest in arid and semi-arid regions. This is unfortunate for people living in those regions. However, it seems the US is being well served by the USGS network for the most part. This good news is countered by the fear on the street about probable cuts to USGS funding.
Most of the world is not as well served with accurate and reliable data as the US.
The window of opportunity to initiate the needed monitoring is closing. The alternative to adequate data is either under-design (unscheduled maintenance and premature failure) or over-design (wasteful over-expenditure or project failure due to inadequate financing). In any case, increased monitoring will be needed to optimize returns on investment; early warning of exceedence of design specifications; and for proactive and adaptive management in an environment of increased uncertainty.