Designing Resilient and Adaptable Water management - Integrated & Interactive Tools (DRAW-IT)

The challenge: Water resources in many UK river catchments are over-allocated, leading to conflict over water and restrictions on some uses during drought events. Pressures on scarce freshwater supplies will likely be exacerbated in future decades as a result of rising demand from population growth, along with increases in the frequency and intensity of droughts due to climate change. To address these challenges, new water supply infrastructure is being planned by many water companies, supported by regional and national model-assisted water supply planning studies. However, such 'water supply infrastructure' models lack sufficient detail to analyse the effects of catchment management measures and their interactions with built infrastructure, such as changing land or agricultural management practices and new policies for water allocation and demand management (e.g. abstraction license reform, water trading, payment for ecosystem services via land management contracts, etc.). A new approach to water resource management is needed in UK water scarce catchments, which utilises custom-designed portfolios of climate-resilient infrastructure and policy measures to support sustainable management of water for businesses and communities, the environment, and agriculture.
Aim: Enable decision-relevant understanding of how new catchment scale assets (e.g. water supply infrastructure), landscapes (e.g. land management and agricultural production systems), and policies (e.g. water sharing and trading schemes) can increase resilience and climate change adaptability of water resource systems, enabling competing demands of limited water resources to be balanced cost-effectively while minimising impacts on the environmental and freshwater ecosystems.
Methods: Connect an extended version (with water trading) of the UK's leading open-source water resource management model (used by 11 water companies) to open-source distributed hydrologic, land-use and agricultural production models. This novel proof of concept interconnected land & water biophysical hydro-economic simulator will be linked to decision analysis under uncertainty approaches, such as multi-criteria trade-off optimisation, to optimise the adaptive adoption of complex portfolios of water-land management interventions in UK catchments. A web-based catchment visualisation tool will enable to toggle back and forth between a map-based catchment intervention portfolio and trading view, and a multi-metric performance dashboard so that stakeholders and decision-makers can assess portfolios of interventions and pre-approved water trades.
Case study: The Cam and Ely Ouse is one of the four pilot catchments identified by the Environment Agency (EA) to trial abstraction reform.
Impact: By designing and implementing a proof-of-concept management approach based on integrated land-water simulation, optimised trade-off based climate change decision-making, and interactive visualisation the project aims to enable a transformation of how catchment level planning (investments, water policies) decisions are made. This could improve the UK's land-water climate resilience, minimising the economic, social and environmental cost of water scarcity under climate change. Given the need to design new environmental conservation subsidies for UK farmers (post-CAP), the proposed outputs will provide an objective framework to understand how different land and agricultural management changes beneficially (or not) impact catchment water outcomes. The approach will be as general as possible to enable subsequent wider application (e.g. to operational drought management (real time water allocation), flood protection, etc.).

Are new reservoirs and inter-regional transfers necessarily the most cost-effective, low-carbon and sustainable routes to achieve water resilience under a changing climate? Should local catchment solutions not also be considered in conjunction with regional infrastructure? If so, land and water managers, regulators and policy makers need tools to collaboratively and iteratively evaluate water-land measure portfolios.

This project will put in place a proof-of-concept management framework including integrated land-water simulation and risk-based decision-making under uncertainty design, which would provide the basis for transformative change in catchment level planning (asset investments and land-use changes) decisions, operational drought policies and management choices (water allocation). Beneficiaries detailed in the pathways to impact include farmers, public water supply customers, environment enthusiasts, environment and financial water regulators, water companies and their shareholders. Below we specify how benefits could manifest.

The public
When expensive and environmentally disruptive water supply infrastructure are selected in lieu of relatively less expensive and disruptive catchment management measures, society pays an opportunity cost. This opportunity cost is their relative difference (how much more the infrastructure solution 'costs' society). Costs can be financial (capital) or economic (scarcity costs) but also foregone opportunities for environmental quality. This could occur because catchment management solutions are not as easily modelled and planned as conventional infrastructure water supply solutions. The proposed project attempts to rectify this.

Farmers, industry and the economy:
Better water management lowers the economic cost of water scarcity. Water scarcity costs manifest through reductions in producer surplus experienced by firms that use water in production and when consumer surplus is decreased by unnecessarily high water rates. Water availability also means businesses can grow unconstrained (by water supply service) and potentially increase productivity. Other economic benefits could include increased land values, higher economic rents, and growth in the visitor economy related to environmental improvements. If the proposed approach were generalised, it could also potentially improve flood control planning, and operational water allocation (e.g. real time drought management and water trading platforms).

Water companies
If water companies face high uncertainty when evaluating water-land catchment management measures they will tend to favour supply-side solutions. Having more sources of water supply, including relatively inexpensive local sources being the fruit of local initiative and innovation (e.g. shared reservoir, water trading, etc.), and more reliable and resilient sources through land management brings down water company costs and uncertainties.

Regulators
Regulators are risk averse. Water rights reform, or 'abstraction license' reform as it is known in England, would entail a potentially relatively risky and costly transition period which could incur significant political and economic costs. The regulators' aim is to minimise these. If resilient and flexible interventions are designed at catchment scale, regulators face less uncertainty over levels of service, and therefore less public pressure and scrutiny. A world with less frequent and severe water scarcity events, because the system has become highly optimised (efficient bundles of measures) and adaptive (water markets intensify under drought to minimise society's scarcity costs) would be a well-regulated one, our goal here.