Planning for drought

The Environment Agency in England recently consulted on water company drought plan guidance. In the UK this framework is continually evolving and supported companies during the 2012 drought along with efforts to increase longer term resiliency. In this blog I comment on this guidance and ask how we can better integrate water resources planning and drought planning?

Long term planning

Better integration is required between drought planning and water resources management plans. A real options analysis approach as part of water resources planning can support development of incremental measures to address the more extreme droughts that we expect with climate change. An example of this approach was presented for Sydney by Stuart White at the International Water Association Efficient 2015 conference (Figure below), whereby a significant costs saving would have arisen through planning for and not building a desalination plant. Similar approaches have already been applied in the UK such as the Thames Estuary 2100 project.

Real Options Analysis approach applied in Sydney, Australia (White, 2015)

This was also my experience working for the Water Corporation in Western Australia during what was at the time the driest year on record (2006). As part of our drought response we utilised a detailed Integrated Resource Planning model to develop short and long term demand management behaviour change programmes to meet the gap between new supply options. Additionally, a broader portfolio of options as part of a “security through diversity” approach was important in enabling Western Australia to have lesser watering restrictions than other states. This has now developed into climate resilient planning. Having a suite of water resources options available as part of drought planning can help in the event of future extreme drought beyond what we traditionally plan for.

Resilience approaches

Resilience is increasingly being recognised by the economic regulator Ofwat and the Environment Agency as essential in the water sector. This was recently defined by an Ofwat task and finish group as:

Resilience is the ability to cope with, and recover from, disruption, and adapt to, trends and variability in order to maintain services for people and protect the natural environment now and in the future.

Resilience is also increasingly a theme for cities in the UK and is being explored as part of the 100 Resilient Cities programme. The interaction between the regional scale drought management responses of water companies and city scale actions need to be considered. This links to land-use planning where decisions on water management for new developments can have a significant impact on how resilient a city is to drought. Water sensitive cities, for example, is an approach that addresses this and considers decentralised options such as water re-use, rainwater harvesting and stormwater management that could reduce pressures on centralised systems. Appropriate plant use in gardens and streetscapes along with bioretention systems that are designed to make best use of any rainfall during drought can bring wider benefits including urban cooling, recreation and amenity(which can now be quantified in a recent tool from CIRIA).

By developing semi-autonomous water supplies throughout cities via new development and opportunistically as part of retrofit programmes we can support a transition towards greater resilience. In the case of the UK this could be implemented through inset appointments and competition, where similar legislation in NSW has led to the Central Park development in Sydney. The new Central Park Water private utility harvests rainwater, stormwater and uses a membrane bioreactor system to reuse and supply 50-70% of the buildings demand (4,000 residents and 15,000 workers/ visitors). A benefit and selling point of this to the development is that is makes it independent of watering restrictions during a drought.

Drought communications plans

The UK Water Industry Research (UKWIR) report Understanding the impacts of drought restrictions provides useful analysis of the first implementation of new temporary use bans (water use restrictions) following the Flood and Water Management Act 2010 coming into force. I presented on this at the CIWEM Annual Conference in 2014 (see presentation). This includes suggestions on how to monitor communications and their impacts. Additionally, a comparison between communications implemented by the different companies impacted by the 2012 drought provides lessons on when to start communications and the best methods.

The analysis was supported by a review of messaging information provided by the water companies and a survey of 1000 domestic customers and 300 non-domestic customers on the impacts of communications. Key findings included that messages from water companies were linked with both domestic and non-domestic customers who had greater knowledge about watering restrictions and changed their behaviour. This suggests water companies should remain the key route for communications around drought measures. Although a minority of households self-identified as confused by the 11 different TUB categories, they subsequently struggled to identify which activities were restricted. This suggests further improvements are required in how we communicate these and look towards longer term messaging around the value of water and water conservation.

Reviewing what has happened during a drought

The UKWIR report also identified a range of data gaps and varying levels of detail between water companies. A top down or bottom up assessment of the impacts of TUBs on water use can be undertaken, however due to flooding events while these were in place during the 2012 drought, neither method provided statistically robust trends. In future, companies who record their communications efforts in more detail may find this easier to match with impacts on demand.

Methods to assess changes in water use during a drought

As we move towards higher levels of smart metering we need to consider what this means for evaluating the impacts of actions taken during a drought. For example, better disaggregation of demand components (e.g. toilet, shower, etc.) within smart meter data and real-time analysis could identify the potential vs actual savings in outdoor use but also better target the larger proportion of domestic consumption that is indoor use.

An example for South East Queensland was presented at the IWA Efficient 2013 conference by Cara Beal. Through the residential end use study (bottom-up) they could determine changes in water use in the home linked with levels of watering restriction. A similar longer-term analysis of smart metering data for households in the UK may provide this information to target restrictions in future.

Water consumption trends with internal and external splits highlighted