What is a decision pattern? A decision pattern is a proven approach to a common water infrastructure challenge. Think of it as a playbook entry: “when you face this problem, here is a strategy that has worked elsewhere, along with the infrastructure it requires, how you monitor it, and the trade-offs to consider.”
Each pattern is linked to use cases (the operational scenarios where it applies) and case studies (real-world examples of it in action). Together, these three layers form the Water Decisions knowledge framework.
How to read this page: Patterns are grouped into categories. Each card shows the problem it solves and a brief description of how it works. Click any card to see the full detail page with infrastructure, monitoring, strengths, trade-offs, and linked case studies.
17
Patterns
4
Categories
15
Use Cases
22
Case Studies
Flooding & Sewage
Strategies for managing floods and sewage overflows — from barriers and tunnels to natural floodplains.
Deep storage tunnels
Problem: Cities with old combined sewer systems overflow raw sewage into rivers during heavy rain. This pollutes waterways and harms public health.
How it works: Large underground tunnels capture overflow during storms and hold it until treatment plants have capacity. The stored water is then pumped out and treated no...
Movable flood barriers
Problem: Low-lying coastal and riverside areas face periodic flooding from storm surges and high tides. Permanent walls would block navigation and access.
How it works: Large mechanical gates or barriers are normally open to allow river flow and shipping, but close when storm surges or high tides threaten. Closure decisions ...
Integrated flood systems
Problem: No single flood defence can handle every type of flooding. Rivers, rainfall, tides, and groundwater can all cause floods, sometimes simultaneously.
How it works: Multiple types of flood infrastructure work together as a coordinated system: barriers, channels, storage areas, pumps, and natural floodplains, all connecte...
Water Supply
Approaches to securing reliable water supply through diversification, storage, and alternative sources.
Integrated water systems
Problem: Relying on a single water source is risky. Droughts, contamination, or infrastructure failure can cut off supply with no backup.
How it works: Multiple water sources — reservoirs, rivers, groundwater, desalination, and recycled water — are connected through a single distribution network ...
Reservoir optimisation
Problem: Reservoir operators must balance competing needs: storing water for dry periods, maintaining flood capacity, and releasing enough to keep rivers healthy.
How it works: Operating rules and models guide how much water to store, release, or transfer based on current levels, weather forecasts, and downstream needs.
Water reuse systems
Problem: Treated wastewater is typically discharged to rivers or the sea. In water-scarce regions, this is a wasted resource that could supplement supply.
How it works: Treated wastewater undergoes additional advanced treatment (microfiltration, reverse osmosis, UV disinfection) to produce water safe for irrigation, industri...
Desalination systems
Problem: Some regions have abundant seawater but insufficient freshwater. Conventional sources (rainfall, rivers, groundwater) cannot meet growing demand.
How it works: Seawater is forced through reverse osmosis membranes that remove salt and contaminants, producing fresh drinking water independent of rainfall.
Demand & Conservation
Ways to reduce water demand and extend supply through behaviour change and community management.
Demand reduction programmes
Problem: Building new supply infrastructure is expensive and slow. In many cases, reducing how much water people use is faster, cheaper, and more sustainable.
How it works: A combination of water restrictions, pricing incentives, public campaigns, efficient appliance standards, and leak reduction to permanently lower per-capita ...
Community water systems
Problem: Remote and rural communities often lack access to piped water. Centralised systems are too expensive to extend to dispersed populations in difficult terrain.
How it works: Local water sources (springs, boreholes) are captured and distributed through simple gravity-fed or hand-pump systems, owned and maintained by the community ...
Monitoring & Data
Sensor networks, data systems, and forecasting tools that underpin informed decision-making.
Continuous monitoring networks
Problem: Without continuous data, operators only discover problems after damage has occurred. Intermittent sampling misses short-lived events like pollution spills or pressure drops.
How it works: Networks of sensors installed across the water system transmit readings in real time to a central control room, enabling immediate detection and response.
Hydrological monitoring networks
Problem: River levels and flows change rapidly during storms. Without continuous measurement, flood warnings come too late and water allocation decisions are based on guesswork.
How it works: Gauging stations along rivers measure water levels and flow rates continuously, feeding data to forecasting models and warning systems.
Predictive modelling systems
Problem: Reacting to events after they happen costs lives and money. Decision-makers need advance warning of floods, droughts, and system failures.
How it works: Computer models combine real-time sensor data with weather forecasts and historical patterns to predict what will happen hours or days ahead, giving time to ...
Smart monitoring networks
Problem: Traditional manual inspections and periodic sampling miss problems between visits. Large networks with thousands of assets cannot be physically checked frequently enough.
How it works: Internet-connected sensors across the water network continuously measure pressure, flow, quality, and other parameters. Data is analysed centrally to detect ...
Water quality monitoring networks
Problem: Pollution from agriculture, industry, and sewage can make water unsafe for drinking, bathing, or ecosystems. Without monitoring, contamination goes undetected.
How it works: Networks of sampling points and automated sensors track parameters like dissolved oxygen, nutrients, heavy metals, and bacteria across rivers, lakes, and coa...
Governance & Planning
Frameworks for coordinating water management across regions, agencies, and competing interests.
National water strategies
Problem: Water challenges cross boundaries between cities, regions, and agencies. Without a national plan, investments are uncoordinated and gaps emerge.
How it works: A government-led strategy sets long-term targets for water supply, flood protection, and environmental quality, coordinating investment across agencies and r...
Basin governance systems
Problem: When multiple users (farmers, cities, industry, environment) draw from the same river or aquifer, over-extraction and conflict are inevitable without rules.
How it works: A governance framework sets extraction limits, allocates water between users, establishes monitoring and compliance systems, and creates mechanisms for resol...
Inter-basin transfer systems
Problem: Water is unevenly distributed geographically. Some regions have surplus water while nearby regions face chronic scarcity, limiting economic development.
How it works: Large-scale infrastructure (canals, tunnels, pipelines) moves water from water-rich regions to water-scarce ones, often across hundreds of kilometres.