Drinking Water From Forests And Grasslands

The U.S. Department of Agriculture’s Forest Service manages more than 779,000 km2 (193 million acres) of national forests and grasslands (collectively, National Forest System [NFS] lands) that play a significant role in providing clean, fresh water for local ecosystems and economies. This water is sometimes transferred hundreds of kilometers away to also serve big cities through inter-basin transfers (IBTs). The contribution of NFS lands to surface drinking water supplies for public water systems has not been assessed at the national scale while accounting for IBTs. The Forest Service Water Supply Stress Index (WaSSI) model was modified to provide estimates of 2001–2015 mean annual surface water supply and the proportion of mean surface water supply originating on 172 NFS land units and other forested lands at the 12-digit hydrologic unit code scale across the conterminous United States (CONUS) while accounting for water transfer through IBTs. Predictions of the proportion of surface water supply originating on NFS and other forested lands were linked to specific downstream communities and populations, using surface drinking water intake information from the U.S. Environmental Protection Agency Safe Drinking Water Information System database of public water systems. A new database of 594 IBTs was compiled for this study, ranging from 0.01 million m3 yr-1 to 8,900 million m3 yr-1, for a total transferred volume of 116,894 million m3 yr-1. Overall, NFS lands comprised 9.2 percent of the total CONUS land area but contributed 12.8 percent of the surface water supply. In the West, NFS lands comprised 19.2 percent of the total land area but contributed 46.3 percent of the 478.7 billion m3 yr-1 surface water supply; in the East, NFS lands comprised about 2.8 percent of the total land area and 3.8 percent (66.6 billion m3 yr-1) of the surface water supply. In total across the CONUS, NFS and other forested lands comprised 28.7 percent of the total land area but contributed 46.0 percent of the surface water supply. Approximately 45.8 million people derived >10 percent of their surface drinking water supply from NFS lands, and 22.6 million people received >50 percent of their surface drinking water supply from NFS lands. Approximately 125.5 million people, about 39 percent of the total population in the CONUS in 2017, derived >10 percent of their surface drinking water supply from NFS and other forested lands, with 83.1 million people receiving >50 percent of their surface drinking water supply from NFS and other forested lands. In addition to those populations receiving surface drinking water supply from their local public surface drinking water intakes, 12.6 million people were served by public water systems that purchased surface drinking water supply from other public water systems deriving >10 percent of their surface drinking water supply from NFS lands. This study provides a systematic accounting of NFS and other forested lands for surface drinking water supply. Our results can aid water resource and forest managers in developing integrated watershed management plans at a time when climate change, population growth, and land development threaten water supplies.

Ground water is the Nation's principal reserve of fresh water and represents much of its potential future water supply. Ground water on National Forest System (NFS) lands is a major contributor to flow in many streams and rivers and has a strong influence on the health and diversity of plant and animal species in forests, grasslands, riparian areas, lakes, wetlands, and cave systems. It also provides drinking water to hundreds of communities. Demands for safe drinking water and requirements to maintain healthy ecosystems are increasing, and complex social and scientific questions have arisen about how to assess and manage the water resources on NFS lands. This technical guide was developed to help address these issues. Today, many of the concerns about ground water resources on or adjacent to public land involve questions about depletion of ground water storage, reductions in streamflow, potential loss of ground water-dependent ecosystems, land subsidence, saltwater intrusion, and changes in ground water quality. The effects of many human activities on ground water resources and on the broader environment need to be clearly understood in order to properly manage these systems. Throughout this technical guide, we emphasize that development, disruption, or contamination of ground water resources has consequences for hydrological systems and related environmental systems. Ground water and surface water are interconnected and interdependent in almost all ecosystems. Ground water plays significant roles in sustaining the flow, chemistry, and temperature of streams, lakes, springs, wetlands, and cave systems in many settings, while surface waters provide recharge to ground water in other settings. Ground water has a major influence on rock weathering, streambank erosion, and the headward progression of stream channels. Pumping of ground water can reduce river flows, lower lake levels, and reduce or eliminate discharges to wetlands and springs. It also can influence the sustainability of drinking-water supplies and maintenance of critical ground water-dependent habitats. Increasingly, attention is being placed on how to manage ground water (and surface-water) resources on public lands in a sustainable manner. The potential for ground water resources to become contaminated from anthropogenic as well as natural sources is being scientifically assessed. Each ground water system and development situation is unique and requires a specific analysis to draw appropriate conclusions. This technical guide begins by reviewing the legislative and policy framework, and the issues related to ground water inventory, monitoring, contamination, and development. Individual sections then focus on key concepts, principles and methods for managing ground water resources. Relevant special topics, case studies, and field examples are highlighted throughout the text. Additional information on some topics can be found in the appendixes. This technical guide provides guidance for implementing the U.S. Department of Agriculture (USDA) Forest Service national ground water policy. It describes hydrological, geological, and ecological concepts, as well as the managerial responsibilities that must be considered to ensure the wise and sustainable use of ground water resources on NFS lands. This document is one part of a four-part information system on ground water management on the national forests and grasslands. The other three parts are (1) Forest Service policy on ground water (Forest Service Manuals [FSM] 2543 and 2880); (2) a Forest Service sourcebook on State ground water laws, regulations, and case law for all 43 States with NFS land; and (3) a ground water inventory and monitoring technical guide. When complete, the four parts will provide line officers and technical specialists at all field levels with the science, policy, and legal framework for Forest Service ground water-resource management.

This book is a printed edition of the Special Issue "Forest Management and Water Resources in the Anthropocene" that was published in Forests

This describes a strategy for conserving National Forest System inventoried roadless areas and their important values. It has an analysis of management options and the Forest Service's preferred alternative.

A global assessment of potential and anticipated impacts of efforts to achieve the SDGs on forests and related socio-economic systems. This title is available as Open Access via Cambridge Core.