Aging water infrastructure, increasing demand, continued land use change, and increasingly extreme weather events are driving the costs of water management higher in the United States. Investing in integrated water management strategies that combine engineered solutions with "natural infrastructure" can reduce costs, enhance services, and provide a suite of co-benefits for communities and the environment. This publication offers comprehensive guidance on the economics, science, partnerships, and finance mechanisms underlying successful efforts to secure the water-related functions of networks of forests and other ecosystems.

Executive Summary

Natural ecosystems like forests and wetlands provide essential services to water utilities, businesses, and communities—from water flow regulation and flood control to water purification and water temperature regulation. To ensure these ecosystem functions and associated benefits continue, communities can strategically secure networks of natural lands, working landscapes, and other open spaces as “natural infrastructure.” While concrete-and-steel built infrastructure will continue to play a critical role in water storage and treatment, investing in natural infrastructure can reduce or avoid costs and enhance water services and security as part of an integrated system to cost-effectively deliver safe drinking water.

Now is a critical moment facing water resource managers and beneficiaries nationwide. Much of America’s aging built infrastructure for drinking water is nearing the end of its useful life. Yet funds for investment in water infrastructure are drying up in an era of fiscal austerity. As utility rates for drinking water are increasing faster than inflation and household incomes, the need is clear for lower cost, integrated solutions to meet water infrastructure demands of the 21st century.

Recognizing this critical moment, water resource managers are looking to invest in ecosystems to address emerging water issues. Promising efforts across the country have secured natural infrastructure for water management objectives through a variety of means—from land acquisition, zoning ordinances, and conservation easements to catastrophic wildfire risk mitigation and payments to private landowners for best management practices. These efforts have yielded a number of valuable lessons and highlighted several challenges.

A number of barriers have impeded efforts to scale up the integration of natural infrastructure into water management nationwide. For example, many utilities, municipalities, and businesses face knowledge gaps among their rate base or even internal decision makers. These entities often lack the financial resources or technical guidance needed to champion natural infrastructure. Moreover, utilities have struggled to quantify the ecological and economic benefits of natural infrastructure, a task made more difficult by imperfect science. Even where the case has been made, public utilities work with financial accounting standards that do not enable operations and maintenance spending on natural infrastructure as part of normal business practices, despite the clear benefits. Ultimately, however, the movement toward widespread, landscape-level investments in natural infrastructure nationwide can be successful if key decision makers in key institutions have the understanding, know-how, and tools needed to act.

In light of these challenges and opportunities, this guide is intended to be a foothold for those who can champion natural infrastructure in water utilities, local conservation groups, and private businesses, and who need a persuasive case, a road map of next steps, and overarching guidance to do so. It attempts to provide the resources, science and economics, illustrations, and guidance needed to foster meaningful dialogue with watershed decision makers and stakeholders around natural infrastructure options, to secure adoption and commitment, and to begin early design and implementation steps on solid footing. It is the most comprehensive publication of its kind to date, pulling together the perspectives of 56 authors spanning the stakeholder groups and experts who need to be involved for natural infrastructure efforts to be successful. As such, it is a go-to reference for their colleagues across the water resource management and conservation fields, agencies at all levels of government, and academia.