CHARLES R. HURSH

Founder, Coweeta Hydrologic Laboratory
Southeastern Forest Experiment Station

Charles R. Hursh (1895 to 1988) was a pioneer in forest hydrology and ecology research in the United States. A native of Jonesboro, IL, with a B.S. from the University of Missouri and a Ph.D. from the University of Minnesota, he was an aggressive research leader whose innovative thinking produced many of the basic principles of wildland hydrology and watershed management.

In the early 1900’s, there was great speculation but scant data among editors and writers about the effects of forests on climate, public health, soil, and stream flow. Concern about soil erosion, flood control, and sustained yields of water led to the establishment of forest reserves and to the passage of the Weeks Act of 1911. The controversy over a forest’s role in regulating stream flow peaked after the Mississippi River flooded in the 1920’s, prompting surveys that showed serious problems with land use, erosion, and flooding throughout the country.

When the Appalachian Forest Experiment Station (now the Southern Research Station) was established in 1921, the Forest Service had no professional foresters with the expertise required to study the effects of forests on soil, climate, or stream flow. A Civil Service examination for ecologists with Ph.D. degrees led to the employment of Charles Hursh in 1926 to develop a watershed research program in western North Carolina.

Hursh’s first goal was to define the characteristics of soil, water, and climate of forested land by accumulating data on small drainages that represented independent hydrologic units. Between 1926 and 1931, he worked on erosion control and stabilization of roadbanks, accumulation of organic matter in soils, and the role of upstream watersheds on the Mississippi River flood. His early research on surface runoff from forests and farmland at the Bent Creek Experimental Forest, combined with his work with an infiltrometer and rainmaker, provided preliminary data on the movement of water through the soil profile.

Hursh believed that "the purpose of the stream flow and erosion study in its broader sense is to determine the principles underlying the relation of forest and vegetative cover to the supply and distribution of meteorological water.¹ By 1932, he had prepared a comprehensive analysis of problems involving forest influences for the mountain and Piedmont regions, and had proposed an approach for solving them. The plan recommended the establishment of long-term hydrologic studies and the development of the Coweeta Hydrologic Laboratory as the research site. Selection of Coweeta was based on the site’s complete drainage of headwater, perennial stream flow, high rainfall, deep soils, and complete forest cover.

The work at Coweeta would begin by establishing two relationships, the first to compare plant cover with stream flow in the absence of erosion, and the second to measure the effects of agricultural land use on erosion and streamf low. Hursh realized even then that his approach would have to be interdisciplinary, involving meteorology, plant physiology, soil science, geology, and hydrology. This complexity required that research be divided into components for critical study, "not only is it impractical to attack the entire problem as a whole, but at the same time it is impractical to attack all of the many factors at one time. Hence, it becomes necessary to determine as a factor for study one that may be considered as fundamental and basic..." For Hursh, the fundamental issue was to determine which cover conditions would produce maximum water yield while ensuring the most effective use of the watershed for power, industrial, and municipal water supplies.

Hursh’s research philosophy was to establish Coweeta as an area in which the impacts of forest management practices on soil and water characteristics could be studied in three phases: first to quantify individual components of the hydrologic cycle on individual watersheds; second, to establish treatments and measure changes in the water balance; and third, to develop and test methods of managing forests for water and other resources. To accomplish these objectives, he foresaw the need for complete instrumentation of watersheds to provide continuous measurements of precipitation, ground water levels, and stream flow.

In 1933, 3,900 acres of the Nantahala National Forest near Franklin, NC, were set aside as the Coweeta Experimental Forest; additional acquisitions eventually brought the total acreage to 5,750.

Creation of a hydrologic laboratory at Coweeta without staffing or money for research equipment was a challenge for Hursh, but he proved to be an opportunist with indefatigable energy. Small in stature, he was a giant in intellect who had a complete intolerance of bureaucratic obstacles. Although permanent Forest Service positions had been frozen, Hursh found another way to employ people with specialized skills--he placed graduate students in 3-month temporary appointments that could be extended infinitely. Confronted with a budget that included zero funding for instruments and equipment, he decided to use the $6 per employee that was allocated for personal equipment, and he interviewed financial officers until he found one who would approve the transaction. During the next six years, using local labor from Federal programs funded during the Great Depression, he constructed roads, offices, shops, a power plant, a hydraulic testing station, and 10 weather stations; he inventoried vegetation; he created a 60-gage network for measuring precipitation; he installed 16 stream gages and 4 ground water wells; he established a nursery to stock road stabilization projects; and he built the first 25 weirs.

By 1939, Hursh had enough records to begin testing the effects of changes in cover using three watersheds. Trees were felled on two of the watersheds, followed on one of the watersheds by clearing for grazing and farming. Hursh’s approach--evaluating effects of treatments by measuring changes in the balance between precipitation and runoff- -was a dramatic diversion from common hydrologic practice, which used the paired watershed method to serve as a check on the total change in stream flow. Before proceeding with their experiments, Coweeta scientists were called to Washington for a review of their entire program by specialists from all regions of the country, partly to explain their research methods and partly to explain why they were cutting good timber and leaving it to rot on the ground.

During the late 1930’s and early 1940’s Hursh worked in collaboration with other outstanding hydrologists like E.F. Brater and M.D. Hoover to shape current concepts of stream flow generation on forestland and to quantify many effects of forest removal on stream flow and water quality. During the next 30 years, he was influential in establishing the concept of a dynamic form of subsurface flow, and he inspired other investigators to take a more integrated approach to stream flow generation on forest lands by including such factors as the variable source area response of watersheds.

Although a strong advocate and master user of the scientific method, Hursh was equally adept and successful in developing solutions to very practical questions. He developed the first successful infiltrometer to study water movement through the soil profile. He developed a concept of municipal watershed management that is now accepted worldwide. But his colleagues report that he derived the most pride from his research on the naturalization of highway roadbanks to control erosion.

The research plan that Hursh developed in 1931 and implemented in 1933 became an internationally renowned hydrologic laboratory during his career and, with little change in direction, has continued as a world leader in hydrologic research for 50 years. Throughout his career, Hursh was an advocate for the maintenance and improvement of environmental quality, serving as a research scholar and a consultant in the United States, France, Japan, Turkey, and Kenya. His contributions to the hydrologic sciences are documented in more than 125 publications, through the long-term results of the research programs he established, and through the many scientists he influenced. In 1953, he received the prestigious Nash Conservation Award.

After his retirement in 1954, Hursh continued to maintain strong and meaningful contacts with his former associates. According to Wayne Swank, current project leader (1991) at Coweeta, "To spend just an hour with Charlie discussing environmental issues was an educational and stimulating experience. The scientific community and our society in general have benefited greatly from his accomplishments."

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