‘One Water’ approach, also referred to as ‘Integrated Water Resources Management (IWRM)’, is the recognition that all water, regardless of its source, has value. It includes “integrated planning and implementation approach to manage finite water resources for long-term resilience and reliability meeting both community and ecosystem needs.”

Present challenges that require a fresh approach towards water:

• Differences in regional water availability: While one region faces drought and water scarcity, the other regions are facing the problem of floods. The groundwater is also getting depleted at a much faster rate.
• Water quality and ecosystem degradation: The rivers, lakes and ponds around cities are increasingly getting polluted. Expansion of cities has led to encroachment of watersheds. Also, inadequate existing infrastructure to accommodate the increased volumes of wastewater leads to flooding, erosion, combined sewer overflows, and habitat destruction.
• Ageing and inadequate infrastructure: Neglected and outdated infrastructure causes a number of water quality problems, from lead in drinking water to contaminated lakes and oceans that suffer from raw sewage overflows.
• Pricing and affordability: Traditional approaches to pricing water do not reflect the true cost of service. Providing multiple subsidies and at the same time covering the cost of supply and upgradation of infrastructure becomes a tedious task.
• Climate change: Changing climate patterns are putting additional stress on water resources and infrastructure. Some communities are suffering from drought as water supplies shrink, temperatures rise, and weather patterns shift, while other communities are experiencing increased flooding and severe storms.

In this context, ‘One Water’ approach can play a significant role in combating such water and urban- ecological challenges:

• Integrated approach: In the conventional water management approach, drinking water, wastewater and stormwater are managed separately, whereas in ‘One Water’, all the water systems, regardless of its source, are connected intentionally and managed meticulously for water, energy and resources.
• Watershed-scale thinking and action: It recognizes that water must be managed in ways that respect and respond to the natural flows of watersheds and the natural ecosystem, geology, and hydrology of an area. Watershed-level management brings together regional partners from within and beyond the water sector in joint planning and collaborative action to protect theshared natural resource.
• Right-sized solutions: It requires a focus on the appropriate scale of intervention to achieve the desired outcome. For example, instead of investing in the creation of just grey infrastructure like dams, reservoirs, etc., more focus is towards building green infrastructure such as rain gardens, bioswales, tree plantings, green roofs, community gardens, green open space, parks, and porous surfaces.
• Inclusive: It is committed to robust community engagement in planning, decision making, and water stewardship. Active collaborations with industry, agencies, policymakers, business leaders and various stakeholders is a regular practice in the ‘One Water’ approach.

Water crisis is identified as one of the top global risks to industries and societies across the world. Only an integrated and multi-faceted collaborative approach towards water has the potential to put a brake to this crisis.