Freshwater Resources in Designated 

Wilderness Areas of the United States: 

A State-of-Knowledge Review

Adam N. Johnson and David R. Spildie

United States Department of Agriculture / Forest Service

Rocky Mountain Research Station

General Technical Report RMRS-GTR-324

June 2014
Rocky Mountain Research Station

Publishing Services

Available only online at http://www.fs.fed.us/rm/pubs/rmrs_gtr324html

Johnson, Adam N.; Spildie, David R. 2014. Freshwater resources in designated wilderness 

areas of the United States: A state-of-knowledge review. Gen. Tech. Rep. RMRSGTR-324. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky 

Mountain Research Station. 32 p.

Abstract

Clean water is essential for ecosystem processes and for the maintenance of human 

populations. However, fresh water accounts for less than three percent of the world’s total 

water volume. Numerous anthropogenic and natural processes impact the quality and 

quantity of the available resource. The value of high-quality water will likely increase as 

threats to water resources expand and human demands increase. In the United States, 

public lands such as forests and grasslands often contain watersheds that have been 

minimally modified by human disturbances. Wilderness areas in particular often provide 

disproportionately large volumes of high quality water. Such regions are critically important for providing water supplies that serve a variety of purposes and uses. The value of 

water draining these lands is arguably higher now than when the National Wilderness 

Preservation System was created 50 years ago. The purpose of this technical report is 

to review currently available information and to encourage future research. The report 

discusses several important topics and themes relating to fresh water resources originating 

in wilderness areas, including: surface water quality and quantity; groundwater resources; 

water uses and benefits; ecosystem services and water valuation mechanisms; potential 

climate change impacts; water-related legislation; and case studies and maps. Case studies 

highlight the societal benefits that may be obtained from water derived from designated 

wilderness areas. A GIS mapping analysis of several regions provides a qualitative view 

of the value of water draining wilderness areas by illustrating the physical proximity of 

high-quality resources to populous regions. Scientific research completed in the last several decades has provided a framework for understanding the contributions and benefits 

of large volumes of high-quality water from wilderness areas for a variety of uses. More 

recent analysis has begun to refine our understanding of these resources in the areas of 

water supply and quantity, water quality, climate change impacts, and ecosystem services. 

However, additional crucial research is needed to document and evaluate the benefits of 

such resources and their importance to ecological vitality, to economies, and to future 

generations.

Keywords: wilderness, water, surface water, ground water, water quality, water quantity, 

ecosystem services, water use, water values and benefits, water supply

About the cover: 

South Fork Flathead River, Bob Marshall Wilderness, Montana (photo by Adam Johnson).
Authors

Adam N. Johnson, U.S. Department of Agriculture, Forest Service, Aldo Leopold 

Wilderness Research Institute, Rocky Mountain Research Station, Missoula, 

Montana. Current email: haulpack@yahoo.com

David R. Spildie, Natural Resources Specialist (retired), U.S. Department of 

Agriculture, Forest Service, Missoula, Montana.

Acknowledgments

We thank the Aldo Leopold Wilderness Research Institute, Rocky Mountain 

Research Station for providing funding for portions of this project. Alan Watson 

(Aldo Leopold Wilderness Research Institute, Rocky Mountain Research Station) 

and Bruce Sims (USFS Region 1) provided helpful reviews that improved the 

manuscript. Peter Landres (Aldo Leopold Wilderness Research Institute, Rocky 

Mountain Research Station) served as the science liaison between the Leopold 

Institute and the Rocky Mountain Research Station to coordinate peer review. 

Nate Johnson assisted with research relating to wilderness legislation and 

special provisions. Thanks to Mirtha Becerra and Emilia Johnson for their support and encouragement.
Table of Contents

Introduction............................................................................................... 1

Purpose...................................................................................................... 2

Wilderness Lands....................................................................................... 4

Wilderness Water Quality.......................................................................... 5

Wilderness Water Quantity........................................................................ 9

Groundwater ........................................................................................... 12

Water Uses, Benefits, and Ecosystem Services......................................... 14

Valuation.................................................................................................. 16

Potential Effects of Climate Change on Wilderness Water Resources....... 17

Case Studies – Wilderness Water and Urban Areas.................................. 18

Case Studies – GIS Mapping..................................................................... 20

Wilderness Legislation and Special Provisions ......................................... 25

Discussion and Conclusions: Wilderness Water Research Needs ............. 29

References ............................................................................................... 31

Figures

Figure 1. Linville River, Linville Gorge, North Carolina 

(photo by Deborah Caffin; source, wilderness.net)................. 3

Figure 2. Frank Church River of No Return Wilderness, Idaho 

(photo by Tom Montoya; source, wilderness.net).................... 3

Figure 3. Cloud Peak Wilderness, Wyoming (photo by Todd Blythe; 

source, wilderness.net). .......................................................... 7

Figure 4. Wilderness contributions to U.S. water supplies and land 

area (modified from Brown and Froemke 2009)................... 11
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Figure 5. Mean depth of contribution to U.S. water supply area 

(modified from Brown and Froemke 2009)........................... 13

Figure 6. Wildland resources and benefits (modified from Gray and 

Young 1984).......................................................................... 14

Figure 7. Holy Cross Wilderness, Colorado (photographer, 

unknown; source, wilderness.net)......................................... 20

Figure 8. Fresno urban area rivers originating in wilderness 

(adapted from Spildie 2003)................................................. 21

Figure 9. Denver urban area rivers originating in wilderness 

(adapted from Spildie 2003)................................................. 21

Figure 10. Sacramento urban area rivers originating in wilderness 

(adapted from Spildie 2003)................................................. 22

Figure 11. Seattle urban area rivers originating in wilderness 

(adapted from Spildie 2003)................................................. 22

Figure 12. Santa Lucia Wilderness, California (photo by Brad Eells; 

source, wilderness.net)......................................................... 24

Figure 13. Ventana Wilderness, California (photo by 

George Wuerthner; source, wilderness.net).......................... 24

Figure 14. Lone Peak Wilderness, Utah (photo by Steve Scheid).............. 25

Figure 15. Mission Mountains Tribal Wilderness, Flathead Indian 

Reservation, Montana (photo by Adam Johnson).................. 26

Tables

Table 1. Water quality in wilderness and non-wilderness 

streams, north-central Wyoming............................................. 8

Table 2. Selected climate-related hydrologic conditions, trends, 

and potential water-related impacts in the Rocky 

Mountain West (modified from Rice et al. 2012).................. 18
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Introduction

Abundant clean water is essential for ecosystem processes and for the maintenance 

of human populations. However, the world’s fresh water (ground water, surface 

water, and atmospheric moisture) accounts for less than 3 percent of the world’s 

water volume, and less than 1 percent of that water is available for human use 

(WBCSD 2006). Renewable sources of fresh water may remain within natural 

systems, as in-stream flow or groundwater stored in aquifers, or the resources 

may be withdrawn for various beneficial uses.

Numerous anthropogenic and natural processes impact water resources. Watershed 

degradation and associated water quality impairments present serious risks to 

human health and quality of life. In fact, water quality impairments have been 

associated with the prevalence of disease (Toch 2000). Multiple processes also 

diminish the quantity of water available for use. The value of abundant supplies 

of high-quality water will therefore increase as threats to water resources expand 

and demands increase (Foti et al. 2010).

In the United States, public lands often contain watersheds that have been minimally modified by anthropogenic disturbances. Land use within units of the 

National Forest system, for example, is often minimal relative to agricultural or 

urban areas. Gifford Pinchot, the first Chief of the U.S. Forest Service (USFS), 

explained that one of the purposes for establishing the first national forests was 

to use them “as great sponges to give out steady flows of water for use in the 

fertile valleys below” (Pinchot 1907). According to the 1897 congressional act 

creating the National Forest System, the purposes of reserving forests were, 

among others, to protect and enhance water supplies and to secure favorable 

conditions of water flows (USFS 2000). Over 60 million people are served by 

public water supply systems located in watersheds containing National Forest 

System (NFS) lands (USFS n.d.).

Former USFS Chief Mike Dombeck (2003) argued that allowing forests to produce high quality water should remain “the highest priority of forest management.” Recognizing the hydrologic alterations and water supply problems that 

may be associated with changes in climate, former USFS Chief Gail Kimbell 

indicated that the agency can “make a difference by managing national forests 

and grasslands to restore ecological processes and functions that support clean 

and healthy streams, lakes, and aquifers” (USFS 2009).
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Purpose

Crucial research is needed to document and evaluate the benefits of wilderness water resources and their importance to future generations. Wilderness 

managers, national non-governmental organizations, local non-profit groups, 

and businesses recognize the critical importance of minimally altered forests, 

grasslands, and other wild areas in providing water supplies for a variety of 

uses. However, these groups may lack sufficient information about the quantity 

and quality of water draining from the nation’s wilderness lands and similarly 

managed areas (Johnson 2003). The purpose of this technical report is to review 

currently available information and to encourage future research.

Some wilderness managers have noted the lack of specific quantitative information regarding the economic benefits from water originating on and draining 

from wilderness lands. Most agency literature and non-profit publications provide only qualitative evaluations. Few studies have employed data collection or 

hydrological modeling activities that resulted in estimates of flow or economic 

benefits from wilderness water (for example, see Brown and Froemke 2009). 

Several problems contribute to the lack of water quality/quantity research in 

wilderness areas; quantification of water needs is a challenging task.

To help fill the data gaps discussed above, and to promote additional research, 

this report discusses several important topics and themes relating to freshwater 

originating in wilderness areas:

•	 A brief discussion of the National Wilderness Preservation System

•	 Water quality and quantity

•	 Groundwater resources

•	 Water uses, benefits, ecosystems services, and valuation mechanisms

•	 Potential climate change impacts on wilderness water resources

•	 Wilderness water case studies, and

•	 Wilderness legislation and special provisions.

The reader should note that wilderness areas may influence water resources that 

cross through, but do not originate within their borders. For example, the Linville 

River passes through the Linville Gorge (Figure 1) in North Carolina, and the 

Salmon River flows through the Frank Church River of No Return Wilderness 

(Figure 2) in Idaho. Although this situation should be considered in evaluations 

of wilderness water, in this paper we focus on headwater drainages in which the 

sources of flow originate in wilderness areas.
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Figure 1. Linville River, Linville Gorge, North Carolina (photo by Deborah Caffin; source, 

wilderness.net).

Figure 2. Frank Church River of No Return Wilderness, Idaho (photo by Tom Montoya; source, 

wilderness.net).
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Wilderness Lands

The U.S. Congress created the National Wilderness Preservation System (NWPS) 

with the passage of the Wilderness Act of 1964 (Public Law 88-577; http://www.

wilderness.net/NWPS/legisAct). The legislation listed the principal purposes of 

wilderness areas (recreational, scenic, scientific, educational, conservation, and 

historical uses) and stated that such areas may contain “ecological, geological, 

or other features of scientific, educational, scenic, or historical value.” Water 

conservation and management for in-stream flows, ecological function, scientific 

values, maintenance of natural conditions, scenic benefits, and recreational opportunities is consistent with the Wilderness Act.

Wilderness within the NWPS is the most protected of all land categories in the 

United States and is managed by four Federal agencies. The U.S. Forest Service, 

the Bureau of Land Management (BLM), the Fish and Wildlife Service (FWS), 

and the National Park Service (NPS), collectively protect more than 750 geographic areas (approximately 110 million acres) across 44 states. In addition, 

significant acreages have been proposed for wilderness designation and/or meet 

the well-known definition of wilderness as specified by the Wilderness Act:

...an area where the earth and its community of life are untrammeled 

by man... without permanent improvements or human habitation... with 

the imprint of man’s work substantially unnoticeable.... (http://www.

wilderness.net/NWPS/legisAct#2).

Nevertheless, the law also allowed for water resource prospecting and the establishment of reservoirs and water conservation works in certain cases. These 

allowances appear to recognize the potential future benefits to human populations provided by the substantial water resources present in wilderness areas. The 

year 2014 marks the 50th Anniversary of the Wilderness Act, and the benefits of 

abundant high-quality water are arguably even more important 5 decades later 

as demand has increased (Foti et al. 2010).

Wilderness and similarly managed areas provide abundant clean water to many 

people (Spildie 2003). For example, many of the areas are within the headwaters of major drainages that provide water to downstream metropolitan areas. 

Generally, wilderness water is of higher quality than drainage from urban and 

agricultural lands (USFS 2002), in part because the sources are situated in 

the basin headwaters. According to Irland (1979), “...protecting wildlands is 

a prime means of protecting water quality. High quality water for agriculture, 

municipal and industrial uses and fish and wildlife habitat is one of the most 

important services of wildland environments.” In addition to providing surface 

water flows, wilderness areas often contain large intact watersheds that recharge 

aquifer systems.
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Wilderness Water Quality

Regions of minimal human development (such as some forests and scrublands) 

are often sources of high-quality runoff (Brown and Binkley 1994), and the 

importance of such water will increase as development proceeds. In general, the 

same can be said of wilderness areas, which typically provide the highest quality water. Surveys by Hass et al. (1986) and Cordell et al. (2008) indicate that, 

of the many reasons for the high valuation of wilderness by citizens, protection 

of water quality consistently receives the highest ranking.

Human activities, development, and pollution sources that degrade water quality 

are largely restricted to non-wilderness lands. Active and abandoned mines, oil 

and gas development, fish facilities, industries, and hazardous waste sites provide 

point sources of pollution. Many of the approximately 38,000 abandoned mines 

and hazardous waste sites on national forests cause significant pollution (USFS 

2000). Common water contaminants include metals, petroleum hydrocarbons, 

pesticides, salts, nutrients, industrial compounds, wastewater treatment plant 

effluents, salinity, and suspended sediment. Changes to various water quality 

parameters such as clarity, salinity, dissolved oxygen, temperature, and suspended sediment may affect downstream uses and benefits (Dissmeyer 2000). 

The high quality of hydrologic resources in headwater areas can in many cases 

be attributed to the general lack of such activities within wilderness boundaries.

Fire management impacts to water quality may include increased sediment, 

turbidity, temperature, and nutrient concentrations (Dissmeyer 2000). Active 

timber management can increase sediment transport, water temperatures, and 

nutrient concentrations due to harvesting and fertilizer application (Cole and 

Landres 1996). Sediment from logging and roads can clog pipes and pumps, and 

cause channel changes, landslides, floods, and debris flows. Corridors such as 

roads, trails, utilities, railroads, and airfields may alter ground water and surface 

water hydrology by increasing the magnitude and frequency of peak flows and 

increasing total runoff and peak runoff rate (USFS 2000). Corridors can also 

cause an increase in erosion and sedimentation and introduce contaminants such 

as metals, hydrocarbons, pesticides, salts, and nutrients.

Concentrated and dispersed recreation may impact water quality through increased sediment transport and human and animal wastes (Perry and Swackhammer 1990). Other potential anthropogenic water quality problems include 

agricultural runoff, livestock grazing, fertilizer application, aquatic invasive 

species, and urbanization (wastewater, urban storm runoff, underground storage 

tanks, abandoned wells, and landfills). Hydromodifications—dams, headgates, 

reservoirs, canals, water wells, diversion ditches, and flumes—can affect physical, chemical, and biological water quality through cross contamination of water 

bodies, loss of habitat, temperature changes, variations in sediment transport, 

eutrophication, and alterations in flow regimes and dissolved oxygen concentrations (Dissmeyer 2000). Natural sources of water quality degradation include 

wildlife, birds, aquatic organisms, wildfire, and microbiological contamination 

such as giardia, cryptosporidium, naegleria, and coliforms, which may also have 

anthropogenic sources (Perry and Swackhammer 1990).
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Water temperature affects chemical interactions and biological activity, and can 

be influenced by overstory removal, revegetation, and stream reconfiguration 

activities. The Clean Water Act mandates that certain water temperature parameters must be maintained. Some reservoirs, for example, must be retrofitted to 

reduce the temperature of effluent water. The necessity of expenditures may be 

tied to the temperature of headwater streams, but also may be due to the nature 

and construction of reservoirs. Temperature and nutrient increases can aggravate 

problems with algae in the form of nuisance and/or toxic algal blooms, and in 

some cases, recreation has been suspended until a solution is found. Wilderness 

water is generally cold, which reduces problems with eutrophication.

Salinity affects almost all water uses by reducing crop yields and damaging appliances and industrial machinery. Water clarity affects aesthetic values and the 

depth of light penetration, which can affect habitat structure. Wilderness water 

may be naturally high in dissolved organic carbon (DOC), which will not cause 

problems for irrigation, but must be removed or treated prior to consumption.

Economic values for water quality changes for various uses can be determined 

using several estimation methods, as discussed below (e.g., Koteen et al. 2002). 

Physical barriers (such as dams) or chemical treatments (such as chlorine) may 

be viewed as necessary interventions. Alternatively, watershed management can 

deal with resource uses that threaten to impair water quality, and may be more 

cost-effective than treatment solutions (Toch 2000).

The general high quality of wilderness water can be attributed to the lack of 

the activities, development, and pollution sources identified above. However, 

we have not identified any studies that explicitly compared water quality data 

from within and outside of designated wilderness lands or similarly managed 

areas. According to Pringle (2001), “there is little information in the U.S. about 

the contribution of wilderness.... to the protection of water quality, either within 

wilderness or for off-site benefits.” One recent study, however, provided some 

limited wilderness water quality information that is useful for comparison purposes. Baseline physical and chemical data were collected at 22 streams within 

and adjacent to the Cloud Peak Wilderness (Figure 3) in the Bighorn Mountains 

of north-central Wyoming (Ferguson 2007; Wilderness Watch 2009; Table 1). 

Snow and precipitation accumulated in the wilderness represent an important 

water resource for municipalities, wildlife, recreation, agriculture, and industry 

in Wyoming. Table 1 also provides data for several non-wilderness streams located within or relatively close to the Bighorn Mountains in Johnson, Bighorn, 

Sheridan, and Washakie Counties (USGS 2012). In addition to draining the 

Cloud Peak Wilderness, the non-wilderness surface water features receive flow 

from areas whose land uses/land cover types include forests, rangelands, and 

other mixed uses.
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Figure 3. Cloud Peak Wilderness, Wyoming (photo by Todd Blythe; source, wilderness.net).

Water quality in the Cloud Peak Wilderness reflects soil types, the local geologic 

setting (glaciated granitic terrains of the Bighorn Mountains), and the lack of 

human-influenced land uses. No point source discharges, reservoirs, logging, 

or motorized uses are present, and only limited seasonal livestock grazing is 

accommodated. Table 1 shows that, in general, water quality is better within 

this mountainous wilderness area than in the lower lying, more intensively 

used areas. For example, specific conductance and alkalinity values are generally lower in the wilderness streams studied. All of the high-elevation streams 

exhibited soft water in contrast to the Tongue and Bighorn Rivers, which were 

moderately hard to very hard, respectively. Wilderness streams also had lower 

sulfate concentrations. The wilderness streams exhibited low chloride, phosphate, 

and total suspended sediment concentrations and low turbidity levels. However, 

since analytical reporting limits varied between studies, comparisons between 

wilderness and non-wilderness data are difficult in some cases.
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Table 1. Water quality in wilderness and non-wilderness streams, north-central Wyoming.
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Wilderness Water Quantity

As illustrated above, wilderness areas typically provide high-quality water for 

in-situ and extractive uses. In many regions of the United States, such lands also 

provide disproportionately high volumes of water relative to non-wilderness land 

uses (Brown and Froemke 2009). These resources support ecological functions 

and are also commodities for downstream users such as irrigators, utilities, 

industries, and municipalities. The protection of human water supplies is one 

important benefit of setting aside wilderness lands.

Altered water flow rates and volumes may affect numerous economic activities 

(Gray and Young 1984). Many of the beneficiaries, however, don’t directly pay 

for the water. In fact, water is not typically priced in the market (Peterson and 

Randall 1984), and payments at the time of use and in proportion to use are 

small or nonexistent (Clawson 1978). Useful quantities are substantial, especially 

where wilderness areas are located near urban centers (Brown and Froemke 

2009; Spildie 2011). Until recently, estimates of nationwide wilderness water 

quantity data were lacking, and rigorous studies of the amount of runoff draining individual wilderness areas in the United States have yet to be completed.

The amount of water available affects both in-situ and extractive uses. Changes 

in water quantity often affect the benefits received by users (Koteen et al. 2002). 

However, until recently few attempts have been made to estimate wilderness 

contributions to water supplies across the nation. U.S. Geological Survey stream 

gages and snowpack telemetry sites within or near wilderness areas may be 

useful for additional research.

Fresh water generally originates as precipitation and then either returns to the 

atmosphere through evapotranspiration, infiltrates to aquifers as groundwater, 

or flows overland to oceans through stream flow. Brown et al. (2008) estimated 

water supply volumes for explicit areas within the 48 states excluding Alaska and 

Hawaii. Water supply was calculated as precipitation minus evapotranspiration. 

The remainder of flow in the hydrologic system was assumed to be surface water 

or groundwater. The study also assumed that mean annual changes in surface 

and groundwater storage (e.g., groundwater pumping, surface water diversions, 

imports to the basin, or groundwater flow out of basins) are negligible. Water 

supply was calculated using several hydrologic models that were calibrated using estimates of precipitation and runoff at 655 monitoring stations across the 

48 states.

Study results indicate that approximately one-fourth of the available water 

supply (two-thirds in the 11 western contiguous states) originates on Federal 

lands under the control of the USFS, BLM, NPS, FWS or Bureau of Indian 

Affairs (BIA). More than half of the water supply for the 48 contiguous states 

originates on forested land, which covers only 29 percent of the surface area of 

the 48 contiguous states. Thirteen states receive more than 70 percent of their 

water supplies from Federal lands. The total water supply in the coterminous 
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United States was estimated to be 1,768 km3/yr (424 mi3), of which 429 km3/yr 

(103 mi3) originates on Federal land. As of September 2004, 117.8 km2 (45,500 

mi2) of the NFS was designated as wilderness (Brown et al. 2005). Using that 

estimate, the volume of water supply originating on NFS wilderness areas was 

estimated to be 66 km3/year (16 mi3/year) or about 25 percent of the total supply from NFS lands.

Alaska and Hawaii were excluded from the Brown et al. 2005 study due to a lack 

of sufficient data. According to The Wilderness Institute et al. (2012), Alaska 

has 48 designated wilderness areas totaling almost 58 million acres, which is 52 

percent of the state’s land area and more than half of all wilderness land in the 

United States. Hawaii has two wilderness areas with more than 155,000 acres 

of wilderness land. Clearly, these two states together provide significant water 

volumes from wilderness areas.

Brown and Froemke (2009) refined the data from Brown et al. (2008) to arrive at estimates of water supply volumes contributed by designated wilderness 

areas in the coterminous United States for the period from 1953-1994. Water 

volumes were based on wilderness land acreages and water supply depths of 

contribution. Calculations assumed that water entering the soil that is not lost to 

evapotranspiration is pumped to the surface or eventually returns to the surface 

at some point downstream and is available for use.

The study found that almost 5 percent of the total U.S. water supply originates 

in designated wilderness areas in a typical year, although these areas represent 

only 2.5 percent of the land area. The estimated average annual depth of supply 

(water supply volume per land area) in the coterminous United States is approximately 230 mm/year (9.1 in/year), and the wilderness depth is almost double 

that amount (approximately 450 mm/year or 17.7 in/year). In USFS Region 6, 

the average depth of supply in wilderness areas is 1,450 mm/year (57.1 in/year) 

(Brown and Froemke 2009).

Because the calculations provided by Brown and Froemke (2009) were based on 

data from weather stations, and such instrumentation is often lacking in wilderness areas, the results are based in part on spatial interpolation between weather 

stations, which introduces calculation errors. Nevertheless, these estimates are 

useful as a starting point for understanding the value that wilderness areas provide in terms of water quantity. Unfortunately, these estimates of water supplies 

(volume per land area) provided by wilderness areas could not be independently 

verified due to the lack of appropriately located stream gages. Future research 

could include the installation and monitoring of gages, and possibly snowpack 

telemetry instrumentation, in one or more strategically located wilderness areas 

to allow for evaluation of the existing water quantity estimates.

The total estimated mean annual water yield from designated wilderness areas is 

approximately 86.5 km3/year (21 mi3) (Brown and Froemke 2009). Figure 4 provides a graphical summary of wilderness area contributions to U.S. water supplies. 
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Figure 4. Wilderness contributions to U.S. water supplies and land area (modified from Brown and Froemke 2009).
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In USFS Regions 1 through 6, such designated areas provide at least 9 percent of 

the water in each region. In the Pacific Northwest and Northern regions (Oregon, 

Washington, northern Idaho, Montana, and North Dakota), more than 18 percent 

of the water volume is provided by wilderness lands. In most cases, the percent of 

water supply provided as a function of the entire regional water supply far outweighs 

the percentage of land area under wilderness designation. As shown in Figure 5, the 

depth of water supply contribution (in mm/yr) is often higher in wilderness areas, 

especially in the western United States. Water volumes from wilderness areas in 

Alaska and Hawaii have yet to be quantified.

Estimates of water volumes derived from wilderness areas can be used for a 

variety of purposes and applications. For example, wilderness managers can 

employ these values to help make decisions regarding individual wilderness 

areas or groups of wilderness lands within different regions of the country. With 

a better understanding of the amount of clean water that flows from relatively 

undisturbed ecosystems in wilderness areas, the public may be more likely to 

support the proposed conservation of additional lands that produce high-quality 

water but that are not currently protected as wilderness.

Groundwater

As discussed above, quantitative wilderness water quality and quantity information is limited. Available studies focus almost exclusively on surface water, 

with little to no groundwater data or investigations identified in the literature. 

Many forests serve as recharge areas for aquifers that supply water for municipal, irrigation, and other needs (USFS 2000). Under the Organic Act, the USFS, 

which manages most wilderness areas, has the authority to manage water, including ground water, under both Federal and state laws. However, the agency 

has historically assumed a limited role in groundwater management on NFS 

lands (Glasser 2007).

According to USFS proposed policy, groundwater should be managed to ensure 

sustainability and long-term resource protection, and assessment and quantification of the resource and groundwater uses are integral components of the 

management strategy (Glasser 2007). However, limited research has been completed to date on the magnitude and quality of USFS groundwater resources or 

their potential value.

Changes in climate over the next century are anticipated to reduce groundwater 

recharge on a global scale (Rice et. al. 2012), but the timing and magnitude of 

such reductions are not well understood. A recent ecosystem services project 

within the USFS (Weidner and Todd 2011) identified watersheds nationwide that 

are most important in terms of their links to drinking water sources. However, 

only surface water sources were considered in the analysis. Despite the wellknown interconnections between groundwater and surface water, groundwater 

was excluded from the study due to a reported lack of national-scale data.
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Figure 5. Mean depth of contribution to U.S. water supply area (modified from Brown and Froemke 2009).
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Water Uses, Benefits, and Ecosystem Services

Water sustains all life on earth. Direct resource benefits to human populations 

include residential, municipal, commercial, industrial, mining, utilities, fisheries, 

commercial (crop) irrigation, household irrigation, and stock watering. In-situ 

benefits or values include recreation (boating, swimming, fishing, camping, and 

wildlife viewing), transportation, waste disposal and assimilation, hydropower, 

subsistence, species and biodiversity conservation, aquatic habitat, and ecosystem function. In addition, several non-use and/or intangible benefits are also 

recognized, including scenery, existence, bequest, therapeutic, and Indigenous 

cultural and spiritual values. Some of these societal benefits are shown in Figure 6. An exhaustive listing of the potential uses and benefits of water derived 

from wilderness areas is beyond the scope of this paper.

Figure 6. Wildland resources and benefits (modified from Gray and Young 1984).
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Depending on the use, some of these benefits are significantly enhanced or 

degraded by changes in water quality and/or quantity, and the various uses require different water quality attributes (Koteen et al. 2002). For example, water 

quantity, salinity, clarity and Total Suspended Sediment (TSS) are important 

parameters for municipal use (residential, public, and commercial purposes). For 

agricultural use, salinity, TSS, water quantity, and temperature are important 

for both producers and consumers. Recreational use is varied, and these activities may be affected differently by multiple water quality parameters. Industrial 

processes use water as a production input for cooling, condensation, washing, 

and transport of materials. TSS, salinity, and water quantity are important 

parameters for industrial uses, and values measured are typically the costs of 

production and benefits to consumers. Water quantity and salinity are important 

parameters for hydropower use (Koteen et al. 2002).

Nonmarket water benefits include onsite use and nonuse (scenery, existence, 

bequest, spiritual, therapeutic, and cultural) values; in these cases, all water 

quality parameters may be important. Other benefits that are difficult to price 

in markets include transportation, waste disposal and assimilation, subsistence, 

ecological continuity, and aquatic habitat, each of which have different water 

quality requirements (Jackson et al. 2001; Koteen et al. 2002; Williams et al. 

1990).

Armatas (2012) identified more than 30 ecosystem services that provide waterrelated benefits to a variety of stakeholders within and near the Shoshone National 

Forest of Wyoming ́s Bighorn Basin. The research identified four stakeholder 

perspectives/viewpoints: environmental, agricultural, Native American, and 

recreation. The water quality ecosystem service was determined to be the most 

important benefit to two of the four viewpoints, and was highly important to 

three of the four perspectives. These results are consistent with earlier surveys 

by Hass et al. (1986) and Cordell et al. (2008) which indicated that protection 

of water quality consistently receives a high ranking by the public. Household 

and municipal use of water was most important to two of the viewpoints, and 

was important to all four perspectives.

The USFS has protected 1.4 million acres of wilderness in five designated 

areas within the Shoshone National Forest. The geographic extent of the study 

by Armatas (2012) includes both wilderness and non-wilderness lands, and the 

investigation was not specifically focused on wilderness areas. Nevertheless, the 

most important ecosystem service identified in the study (water quality) can be 

directly tied to the existence of large tracts of relatively pristine wilderness in 

Shoshone headwater areas. The high quality of water for household and municipal 

use (the other most important identified ecosystem service) can also be linked 

to wilderness lands within the forest. Other ecosystem services identified by 

Armatas (2012) that owe their utility in part to the existence of wilderness lands 

within the study area include recreation; preservation of livelihoods, lifestyles, 

and landscapes; Indigenous cultural and spiritual values; river-based fishing; 

conservation of species and biodiversity, and glacier-based ecosystem services.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 16

Valuation

One definition of the benefit or value of a water resource is “the amount that a 

perfectly rational and well-informed user...would be willing to pay for it” (Gray 

and Young 1984). However, the physical characteristics of water, including its 

mobile, transient, and fluid nature, make market valuation of the resource difficult. The dimensions of quantity, quality, time, and location are important 

components of the valuation problem, and water may be used beneficially for 

multiple purposes at different locations and multiple times. Total value is considered to be a sum of the net positive benefits and negative consequences of 

water use (Gray and Young 1984), and the benefits of wilderness water extend 

beyond those that can be priced in markets.

Water quality modifications impact the benefits received, and some of these 

benefit changes can be quantified (Koteen et al. 2002). Varying numbers of parameters are necessary to define water quality depending on the intended use(s). 

Changes in water quality affect multiple uses differently, and both producers and 

consumers of water benefit or suffer from water quality changes. High quality 

water and temporal constancy of water quality parameters minimize costs associated with managing, purifying, and distributing water. Hydrologic contributions 

from wilderness often fulfill these requirements (e.g., USFS 2002). Wilderness 

ecological services include protection of watersheds and water quality (Loomis 

and Richardson 2001).

Placing an economic value on wildland water can be accomplished using several 

market and non-market techniques. Water for agricultural and industrial use, for 

example, is an input into production processes that ultimately yield final goods 

(Peterson and Randall 1984). Values can be more easily calculated for these 

water uses than for non-market uses. For example, economists can calculate the 

cost savings to municipal water treatment agencies and water users if the quality 

of the input is high. Pure source waters lower the cost of treatment in terms of 

settling basins, sediment precipitators, and filtration technology. New treatment 

facilities can cost over $50 million, with at least $3 million in annual operating 

costs (Loomis et al. 2000). The savings due to prevention of sediment transport 

ranged from $130,000 to $260,000 from one national forest. If generalized to 

wilderness acreage, the cost savings could range from $9 to $18 million (Loomis 

and Richardson 2001). Headwater drainages (where most wilderness areas are 

located) also generally exhibit low levels of dissolved solids and contaminants, 

and water resources generally need lower levels of treatment than water from 

lower in the watershed (Dissmeyer 2000).

The contingent valuation method involves asking people who benefit from watershed protection (clean water) what they would pay for that service (Loomis et 

al. 2000). Contingent valuation uses simulated markets to estimate values people 

place on water quality changes. The travel cost method, which measures actual 

recreation behavior in terms of transportation and travel time costs (Brown 1991), 

can be used to compare sites that have different water quality characteristics. 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 17

Hedonic pricing techniques have been used to estimate the effect of water quality changes on property values (Koteen et al. 2002).

A conservative estimate of the annual marginal value of water flowing from 

the national forests is $3.7 billion (USFS 2000). The marginal value for the 

consumer is the price for a good, while the total value is the benefit to society 

of producer and consumer surpluses (Koteen et al. 2002). For the Forest Service study, water flow was determined with a quantitative model that estimated 

runoff in each USFS region. Water values were derived from estimates used for 

off-stream purposes ($40 per acre-foot), instream flow in the west ($17), and 

recreation and hydropower in the east ($8). The number above is a conservative estimate because the average value is greater than the marginal value, and 

because dilution, navigation, moderation of downstream flooding, water quality, 

and non-use values were not considered. In addition, the current marginal value 

is likely higher as urban development continues and populations rise.

Brown (1991) discussed additional types of wilderness water benefits that are 

more difficult to quantify but nevertheless contribute to the overall value of the 

resource. These include:

•	 Preservation and existence values: for example, the willingness to pay for 

the knowledge that a certain level of stream flow is preserved in a given 

wilderness area. Both citizens who recreate on the river and those who 

may never visit the wilderness may hold this value.

•	 Bequest value: a willingness to pay for preserving in-stream flows for 

future generations.

Potential Effects of Climate Change on 

Wilderness Water Resources

Little quantitative information is available regarding the potential impacts of a 

changing climate on water resources in wilderness areas, although some studies 

have been completed for U.S. water resources in general. Rice et al. (2012) indicated that a temperature increase of between 2 and 4 oF (1 to 2 oC) was observed 

in the Rocky Mountains of the western United States during the 20th Century. 

During the same period, researchers documented declines in precipitation and 

reductions in snowpack volumes. Temperatures are expected to rise an additional 

2 to 10 oF (1.1 to 5.5 oC) in the 21st Century. Potential future impacts on water 

quantity and quality, stream flow, glaciers, snow, and wetlands are described 

in Table 2. Although these anticipated changes to the hydrologic cycle are not 

exclusive to wilderness areas, many will have a disproportionate impact on 

wilderness due to their locations in high-elevation headwater drainages.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 18

Armatas (2012) discussed potential climate change vulnerabilities in the Bighorn 

Basin of Wyoming with respect to ecosystem services that support a variety 

of uses. Many stakeholders involved in the study recognized climate change as 

a possible threat to water-based ecosystem services within the Bighorn Basin.

Case Studies—Wilderness Water and Urban Areas

The following examples highlight the societal benefits that may be obtained 

from water derived from designated wilderness or similarly managed areas. Each 

case illustrates the real or potential economic value created by the proximity of 

high quality water to urban areas.

Table 2. Selected climate-related hydrologic conditions, trends, and potential water-related impacts in 

the Rocky Mountain West (modified from Rice et al. 2012).

Variable 20th Century trend

Anticipated 21st Century 

response

Potential impacts on 

ecosystem services

Surface water 

quantity

Decrease in annual 

flows in MT and WY 

since 1967

Increase in peak flows; 

decrease in summer flows 

and annual flows

Greater flood magnitudes; 

loss of habitat from reduced 

stream flow; reduction in flows 

for water supply; increased 

groundwater use

Surface water 

quality

Variable water quality 

conditions nationwide

Decreased flows could increase chemical loads and 

disturbances may increase 

sedimentation.

Reductions in quality; increases in temperature (reduction 

in habitat quality); increased 

algae and higher water treatment costs

Stream flow 

timing

More than 10 days 

earlier since 1967 in 

some areas

4 to 5 weeks earlier in 

some regions

Change in the timing of flows 

available for water storage 

and recreation

Glaciers Ice mass reductions; 

temporary mitigation 

of stream flow reductions

Loss of glaciers with 

subsequent stream flow 

reductions and increases 

in stream temperatures

Reduced water supplies; 

reductions in summer stream 

flows; decreases in water 

quality (increases in sediment 

and temperature).

Snow Declining snow volume; earlier annual 

snowmelt

Significant snowpack loss Decreased volume for water 

supply; altered timing of water 

flows for storage

Wetlands Wetlands lost and 

wetland areas reduced

Continued wetland losses 

due to reduced precipitation, earlier snowmelt, and 

increased evaporation

Reductions in groundwater 

recharge and groundwater 

elevations
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 19

San Francisco, California, receives approximately 85 percent of its water from the 

Hetch-Hetchy Reservoir system, a series of watersheds originating in Yosemite 

National Park (SFPUC 2013). The San Francisco Water Department was originally ordered to build a $500 million filtration plant, which would have doubled 

residential and commercial water bills. However, California’s first filtration 

exemption was granted based on the quality of the natural source, which is attributed to the fact that the majority of the watershed is under Federal protection 

and sustains limited human land use. Ecological functions (e.g., intact soils and 

indigenous vegetative cover) serve as natural purification devices.

In the 1990s, the U.S. Environmental Protection Agency (EPA) ordered New 

York City to build a filtration plant at a cost of $6 to $8 billion. Instead, the city 

was able to avoid construction of the costly facility and today is managing the 

Delaware/Catskill and Croton watersheds for water quality protection. Management actions include prevention of development and land acquisition within 

the catchments. The Catskill/Delaware watershed project, completed in 1964, 

worked well prior to land development but tourism and suburban expansion compromised water quality. In 1989, the EPA released the Surface Water Treatment 

Rule, which required filtration unless human activities in the watershed could 

be controlled. The EPA’s rule gave financial value to the Catskills’ natural water 

purification services (Daily and Ellison 2003; USFS 2002).

The Bull Run surface water source in Portland, Oregon, also meets criteria for 

avoiding filtration. To qualify for the exemption, a watershed control program 

is required, and the water must pass tests for coliform bacteria and turbidity. 

Although the Bull Run area was logged for several decades, no public entry or 

commercial activity is currently allowed. These restrictions, as well as the geologic 

and ecological characteristics of the watershed, contribute to the high quality 

of the resource. Although an attempt to find the economic value of protecting 

this watershed was unsuccessful (Robbins et al. 1991), building, maintaining, 

and operating a filtration plant would cost the city about $3 million per year.

Water developers have noted the great potential for development of the resource 

within and adjacent to wilderness areas (“water warehouses”) because of both 

elevation (gravity drainage reduces costs and energy usage that would be required 

for pumping) and temperature (volumes lost to evaporation are smaller) (Williams 

et al. 1990). Under the terms of the legislation creating the Holy Cross Wilderness (Figure 7) in Colorado, Congress affirmed the water rights of two cities: 

Aurora and Colorado Springs. Water in high mountain streams was scheduled 

for diversion and delivery. After public controversy and court battles, the project 

was suspended. Some large municipalities such as Denver, Colorado, use full 

treatment but the quality of supplied water is consistent. Water flowing from 

wilderness areas is often not subject to major temporal water quality changes.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 20

Case Studies—GIS Mapping

A pilot project completed at the Aldo Leopold Wilderness Research Institute 

(Spildie 2003) leveraged Geographic Information System (GIS) data to illustrate 

the locations of several wilderness areas and their hydrographic connections with 

the Fresno, California urban area (Figure 8). This study provides a qualitative 

view of the value of water draining wilderness areas and illustrates the physical 

proximity of the high-quality resources to this populous region. Further research 

could be completed to quantify both the extent of the City of Fresno’s wilderness water use for various purposes and the value of the resource. Subsequent 

mapping provides a qualitative understanding of the contribution of wilderness 

water to the cities of Denver, Sacramento, and Seattle (Figures 9-11). These maps 

illustrate the spatial relationship between urban areas and headwater streams 

originating in wilderness (Spildie 2003). Many other population centers also 

receive water from wilderness areas. Initial attempts at quantification could 

include, for example, a tabulation of the number of hydrologic unit codes that 

lie inside wilderness boundaries. Although little quantitative information is 

available regarding direct or indirect groundwater contributions from wilderness lands to high-population areas, such data could prove crucial for ensuring 

sound management of urban water sources in the future.

Figure 7. Holy Cross Wilderness, Colorado (photographer, unknown; source, wilderness.net). 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 21

Figure 8. Fresno urban area rivers originating in wilderness (adapted from Spildie 2003).

Figure 9. Denver urban area rivers originating in wilderness (adapted from Spildie 2003).
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 22

Figure 10. Sacramento urban area rivers originating in wilderness (adapted from Spildie 2003).

Figure 11. Seattle urban area rivers originating in wilderness (adapted from Spildie 2003).
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 23

Wilderness Legislation and Special Provisions

Although the 1964 Wilderness Act prohibited most forms of development within 

wilderness boundaries, subsequent legislation has recognized the human need 

for water resources that originate within those boundaries. For example, certain 

wilderness laws allow for the operation, maintenance, and repair of dams and 

other water impoundment facilities, and others provide for hydrologic monitoring for flood warning systems, flood control, and water reservoir operations. 

Snow pack telemetry equipment in some headwater areas provides information 

useful for the management of downstream hydroelectric projects. In some cases, 

hydrologic, meteorological, and/or climatological instrumentation (including 

snow sensors and stream gages) was deemed appropriate to further wilderness 

scientific, educational, and conservation purposes. These provisions, and areaspecific provisions discussed below, implicitly recognize the value of wilderness 

water to society.

In addition, the use, operation, maintenance, repair, modification, or replacement 

of water resource facilities existing at the time of wilderness designation has 

generally been deemed acceptable. The term ‘‘water resource facility’’ typically 

includes irrigation and pumping facilities, reservoirs, water conservation works, 

aqueducts, canals, ditches, pipelines, wells, hydropower projects, transmission 

facilities, and other water diversion, storage, and transportation structures.

Some wilderness designation laws indicate that specific downstream uses of 

water that originates in wilderness areas are protected. For example, the Arizona Desert Wilderness Act of 1990 indicates that an existing water pipeline 

within the Mount Nutt Wilderness that serves the town of Oatman, Arizona 

can be operated, maintained, and upgraded. The Utah Wilderness Act of 1984 

authorized sanitary facilities to ensure the health and safety of the communities 

serviced by the watersheds emanating from 10 wilderness areas. The Act also 

allows access for activities necessary to prevent watershed degradation.

The Colorado Wilderness Act of 1980, which created the Holy Cross Wilderness, ensured that the diversion and use of existing water rights for the Homestake Water Development Project by the cities of Aurora and Colorado Springs, 

Colorado, would not be altered by its passage. The legislation also allowed the 

construction, operation, maintenance and repair of the Homestake project. According to the Endangered American Wilderness Act of 1978, no rights to the 

diversion and use of the waters of Hunter Creek, the Fryingpan or Roaring Fork 

Rivers, or any tributaries of said creeks or rivers, by the Fryingpan-Arkansas 

Project were to be altered by the legislation. The Fryingpan-Arkansas project 

provides water to the Arkansas River Basin and the cities of Aurora and Colorado 

Springs through a series of diversion structures. The project is managed by the 

U.S. Bureau of Reclamation and the Southeastern Colorado Water Conservancy 

District. The current annual diversion volume is approximately 58,000 acre-feet.
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 24

The Endangered American Wilderness Act authorized the USFS to take appropriate actions to protect the California Santa Lucia and Ventana Wilderness 

watersheds (Figures 12, 13) and the health and safety of downstream communities. 

The USFS was also directed to “take whatever appropriate actions are necessary 

for ...watershed protection...” Under the same law, sanitary facilities are to be 

used to ensure the continued health and safety of the communities served by the 

Lone Peak Wilderness (Figure 14) in Utah. Access is allowed for the purpose of 

guaranteeing the continued viability of existing watershed facilities to prevent 

the degradation of water quality in the Lone Peak area.

Figure 12. Santa Lucia Wilderness, California (photo by Brad Eells; source, wilderness.net).

Figure 13. Ventana Wilderness, California (photo by George Wuerthner; 

source, wilderness.net).
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 25

Figure 14. Lone Peak Wilderness, Utah (photo by Steve Scheid).

Gorte (2011) provided a legislative summary of wilderness special provisions 

and prohibited/permitted uses within wilderness areas. Numerous statutes have 

allowed for operation and maintenance of existing water resources infrastructure 

(dams, canals, pipelines, and other improvements), and some laws have allowed 

for the construction of new water-related facilities, including hydroelectric 

generators and power projects, water development and conservation structures, 

improvements and upgrades to existing water distribution systems, dams and 

reservoirs, water sources for livestock and wildlife enhancement purposes, and 

fish-related structures. In some cases, Federal water rights have been expressly 

reserved to fulfill the purposes for which the areas were designated.

Non-Federal designated wilderness areas also provide high quality water to 

downstream communities. The Mission Mountains Tribal Wilderness (Figure 15), 

established by the Confederated Salish and Kootenai Tribes in 1982, was the first 

such tribally designated area in the United States (CSKT 2005). The 92,000-acre 

region in northwestern Montana is the source of some of the cleanest water on 

the Flathead Indian Reservation, and includes nine major streams and more than 

100 lakes. The tribal community depends on this water for drinking, fishing, 

agriculture, the maintenance of spiritual and cultural traditions, and other uses. 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 26

Non-Indian residents of the reservation also benefit from wilderness water for 

drinking and agriculture. Municipal watershed protection is given special consideration during the wilderness management decision-making process within 

the tribal government. For example, the town of Ronan, Montana, maintains a 

municipal water supply lease on Middle Crow Creek, which originates in the 

Mission Mountains Wilderness.

States have also set aside lands to protect water quality. For example, in 1892 

the State of New York reserved a large area in the Adirondack Mountains, and 

one of the justifications for land preservation was the protection of valuable 

water resources (New York State 2012). The Adirondack Park was created amid 

concerns for the water and timber resources of the region. The park consists 

of approximately 6 million acres, more than 3,000 lakes, and 30,000 miles of 

rivers and streams. The state owns approximately 43 percent of the land within 

the Park’s boundaries. The remaining private lands are devoted principally to 

forestry, agriculture, and open space recreation. Although the park is not officially designated as wilderness, water quality protection and remains a high 

priority in the Adirondacks.

Figure 15. Mission Mountains Tribal Wilderness, Flathead Indian Reservation, Montana 

(photo by Adam Johnson).
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 27

Discussion And Conclusions: 

Wilderness Water Research Needs

Until recently, wilderness water discussions at the Federal level were generally 

limited to sections of publications concerning multiple wildland values or conference proceedings that focused on water quality impacts within the boundaries of individual wilderness areas. Recent research is beginning to refine our 

understanding of water resources in the areas of water supply and quantity, 

water quality, climate change impacts, and ecosystem services. The information reviewed in this paper illustrates the importance and increasing scarcity of 

high quality water resources across the nation. However, Pringle (2001) stressed 

the need for additional information about the contribution of wilderness to the 

protection of water quality, and noted a “lack of data on hydrologic connections 

between wilderness and surrounding areas...”

The Forests to Faucets project (Weidner and Todd 2011) identified forested areas 

that protect drinking water and regions where water supplies are threatened by 

development, wildfires, and insects and diseases. The study distinguished between all forested lands, NFS lands, unprotected private forests, and protected 

forest lands. Wilderness areas were considered in the analysis as part of the 

national Protected Areas Database. The authors created an Index of Protected 

Forest Importance to Surface Drinking Water, which explicitly recognizes the 

contribution of protected areas (including wilderness) to high-quality surface 

water for drinking purposes. However, the authors note that the results of the 

study are intended to provide broad-scale information across the country, and 

should not be used at the scale of individual watersheds. Additional basin-scale 

data and information is needed to understand connections between forests, 

drinking water sources, and threats to the forested areas.

Potential users of water research results include managers of wilderness lands 

and non-profit organizations that have asked for quantitative studies on the 

benefits of the resource. Work recently completed by Federal researchers is a 

partial response to such requests. Results of additional research can be used 

to better educate the public on the need for wilderness preservation and sound 

management. A high-visibility discussion (such as an article in Natural Areas 

Journal or a similar publication) may provide an avenue for receiving feedback 

regarding possible research approaches, recruitment of collaborators, and funding sources for projects.

New water resource valuation research could focus on multiple scales. In the 

broadest approach, values could be characterized across the country. Indeed, a 

major research need is the refinement of national water yield and value estimates 

on the national forests (USFS 2000), although more recent research by Tom 

Brown has provided some relevant information (Brown et al. 2005, 2008; Brown 

and Froemke 2009). Certainly, more refined estimates of wilderness water flows 

and values will be very useful. Alternatively, research on specific wildernesses 

or similarly managed areas (see case studies above) would undoubtedly also 
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 28

provide helpful information. For example, a study could be designed to rigorously 

quantify water volumes, water quality attributes, and economic values/benefits 

in one or more pilot wilderness study areas. More specifically, quantification 

of groundwater recharge to agricultural regions or urban zones from specific 

wilderness areas would provide significant insight into water valuation. Hydrogeologists and hydrologists could develop coupled surface water-groundwater 

conceptual and numerical models for one or more specific wilderness areas to 

quantify volumes and temporal variations in groundwater flows. These scientists 

could then work with natural resource economists to develop preliminary estimates of the value of the groundwater resources. Another study could highlight 

management needs to address existing unnatural fuel loads and address the effects of fire suppression that may be putting wilderness watersheds at increased 

risk of large, severe wildfires. Prescribed fires may be necessary in some cases 

to reduce risks to watershed function.

Water resources management strategies and research priorities vary across the 

agencies controlling wilderness lands. For example, the Forest Service is actively involved with developing plans for improving water resources protection 

and management within the National Forests, while the National Park Service 

maintains several significant service-wide programs concerning both water 

quality and water quantity protection. Development of an interagency panel of 

wilderness managers focused on water issues (similar to the Interagency Wild 

& Scenic Rivers Coordinating Council) may be one way to focus more attention 

on this important topic.

In summary, scientific research completed in the last several decades (and in 

the last 10 years in particular) has provided a framework for understanding the 

contributions and benefits of large volumes of high-quality water from wilderness areas for a variety of uses. However, much more can be done to improve 

our knowledge of the hydrologic characteristics of these areas and their contributions to economic and ecological vitality. As Pringle (2001) wrote, “the role 

of water, both aboveground and below the surface, must become a more integral 

consideration of wilderness integrity.”
USDA Forest Service Gen. Tech. Rep. RMRS-GTR-324. 2014 29

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Watson, A.E. Aplet, G.H., and Hendee, J.C., comps. Personal, societal, and ecological values 

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