Water, Air and Soil
Water is one of the most important commodities on Forest Service lands, and the cleanest water flows from healthy, forested watersheds. The most effective way to approach ecological issues is to consider them at a watershed level.
Air, like water, is inseparable from the health of natural resources. Poor air quality decreases visibility, acidifies or disrupts the nutrient balance in lakes and streams, injures plant and animal communities and harms human health.
Healthy soil absorbs water and makes it available for plants, cycle nutrients and filter pollutants. Soil also controls water flow and stores and cycles nutrients. Soil is the basis of our ecosystem and controls living things above and below the surface. Soil is the core of National Forest Land Management Systems. Our goal is to insure that we maintain clean water, air and productive soils to assure a healthy forest.
What is a Watershed?
It is the drainage area of a landscape where water from rain or melting snow and ice drains downhill into a body of water such as river, lake, reservoir, pond, estuary, wetland, aquifer, sea, or ocean. Watersheds include the streams, lakes and shallow aquifers that store and convey the water as well as the land surfaces from which water drains and the aquatic ecosystems that they support. Topography and geology determine where the water flows, and thus are used to separate adjacent drainage basins into a hierarchical structure in which small watershed drain into progressively larger ones.
Watershed Information
Functional watersheds are essential for healthy streams and clean water. Healthy forest watersheds absorb snow and rain, store and filter it in the soil, and yield clean water to streams and ground water. Forests must be renewed and cared for over time to sustain good watershed function. Conservation leaders have understood these simple truths for over 100 years.
Healthy forest watersheds function in dynamic balance. Soil and stream conditions usually vary within a limited range. They rebound promptly from natural disturbance events like wildfires and floods – just as healthy people rebound quickly from mild illnesses. On rare occasions, severe fires or floods can throw even healthy forest watersheds out of balance. Resilient forest watersheds usually recover from such “re-set” events within several years.
Fire is natural in the ecology of western forests. For example, most ponderosa pine forests are sustained by frequent, low-intensity surface fires that knock back undergrowth and promote open stands of large trees with grassy understory. On the other hand, lodgepole pine forests are commonly regenerated by infrequent but intense crown fires that kill the mature trees but promote abundant seed-fall (and aspen sprouting) to quickly establish the next forest. Natural fire cycles create diversity in the types, ages, and densities of trees. This diversity helps limit soil damage from severe fires.
Over many decades, people have made choices that have left forests less healthy and more prone to severe fires. In ponderosa pine forests, for example, a century of fire exclusion has let many trees crowd the forest and build up heavy fuel loads near the ground. In lodgepole pine forests, large natural and human-caused fires in the 1800s led to vast uniform tracts of mature, even-aged forests that are highly susceptible to beetle attacks and mega-fires.
In both cases, watershed function is intact as long as the forests do not burn. But recent forest fires have tended to be much larger and more severe than those in the past. Such severe fires bake the soil, throw watershed function out of balance, and lead to heavy erosion and sediment damage in streams.
A vivid example is the Buffalo Creek Fire of May 1996 (near Denver, CO). This fire severely burned the Spring Creek watershed because ponderosa pine forests were crowded with small understory trees and heavy surface fuels. Barren, water-repellent slopes were exposed to repeated heavy rain storms. Rapid runoff produced over a dozen 100-year floods in Spring Creek from 1996 to 2009. The watershed is still out-of-balance and not properly functioning. Several watersheds burned by the epic Hayman Fire of 2002 suffered similar results. How long these watersheds will remain out-of-balance is unknown.
Functional watersheds are vital to protect water resources from post-fire flood damage. Careful forest treatments can increase resilience to forest fires and help protect watershed function. Thinning, patch cuts, and prescribed fires conducted in strategic places over time create a diverse forest mosaic of tree types and ages that will temper the extent and severity of forest fires. Leaving out-of-balance forests alone poses high risks to watershed function, water supply, and the water storage and delivery facilities that now intersect most forests.
Organic Administration Act of 1897 (16 U.S.C. 475)
This law defines the original purposes of national forests – to improve and protect the forests, to furnish a continuous supply of timber, and to secure favorable conditions of water flows. Years of concern about watershed damage led to creation of the national forests. Watersheds must be cared for to sustain their watershed function as “sponge-and-filter” systems that store water and naturally regulate runoff. The goals are good plant and ground cover, streams in dynamic balance with their channels and flood plains, and natural conveyance of water and sediment.
Multiple Use-Sustained Yield Act of 1960 (16 U.S.C. 528)
This law amplifies national forest purposes to include watershed, wildlife and fish, outdoor recreation, range, and timber. Renewable surface resources must be managed for multiple use and sustained yield of the several products and services they provide. The principles of multiple use and sustained yield include the provision that land productivity shall not be impaired.
Endangered Species Act of 1973 (16 U.S.C. 1531-36, 1538-40)
This law was written to conserve endangered and threatened species of wildlife, fish, plants, and the ecosystems on which they depend. Federal agencies must conserve endangered & threatened species in cooperation with state and local agencies. Conservation means using all means needed to recover species to where the measures provided pursuant to this law are no longer needed. Each agency shall ensure that actions are unlikely to jeopardize the continued existence of any endangered or threatened species or result in adverse modification of their critical habitat.
National Forest Management Act of 1976 (16 U.S.C. 1600-02, 1604, 1606, 1608-14)
This law was written to guide forest planning and management. Programs must protect and, where appropriate, improve the quality of soil and water. Timber must be harvested only where soil, slope, and watershed conditions are not irreversibly damaged; the land can be adequately restocked within five years after harvest; and streams, lakes, wetlands, and other water bodies are protected from detrimental impacts.
Federal Land Policy and Management Act of 1976 (43 U.S.C. 1752)
This law was written to guide management of national forests and grasslands. These lands must be managed to protect ecological, environmental, air, water resource, and other values, and provide food and habitat for fish, wildlife, and domestic animals. Rights-of-way and uses shall include terms and conditions to protect the environment, subject to valid existing rights.
Clean Water Act of 1977 (33 U.S.C. 1251, 1254, 1323-24, 1329, 1342, 1344) This series of laws was written to restore and maintain the chemical, physical, and biological integrity of the nation’s waters. The goal is to sustain the integrity of water quality and aquatic habitat so that waters of the United States (perennial and intermittent streams, lakes, wetlands, and their tributaries) will support diverse, productive, stable, aquatic ecosystems with a balanced range of aquatic habitats. The Forest Service must comply with water quality laws and rules like anyone else and must apply best management practices to protect water quality.