The effects of urbanization are more tangible and better recognized than those of agricultural land-use. Streams that flow through cities and other populous areas undergo some modification, especially of the streamside flora. Another effect of urbanization has been increased loads of sewage discharged into the streams. The combined populations of Arkansas City and Winfield rose from 3,986 in 1880 to 23,167 in 1950. Arkansas City found it necessary to construct a sewage system in 1889; Winfield in 1907. There are, at the present time, nine towns within the area that have municipal sewage systems. The State Training Home at Winfield also has a sewage system. The Kansas State Board of Health, Division of Sanitation, has provided information concerning adequacy of these systems and certain others in nearby counties as of February 5, 1957. This information is shown in Table 3. Representatives of the Division of Sanitation, Kansas State Board of Health, expressed the belief that pollution by both domestic sewage and industrial wastes would be largely eliminated in the "lower Arkansas" and in the Walnut watershed by 1959. Important oil and gas resources have been discovered in each of the three counties. The first producing wells were drilled between 1900 and 1902 (Jewett and Abernathy, 1945:24). The Arkansas River flows through several oilfields in its course across Cowley County (Jewett and Abernathy, 1945:97). A number of producing wells have been drilled in the Grouse Creek watershed since 1939 and many of these wells are near the banks of the creek. In the Big Caney watershed of Cowley and Chautauqua counties there has been little oil production in recent years; however, a few small pools are presently producing in southwestern Elk County. Clapp (1920:33) stated that "Many of the finest streams of our state are now destitute of fish on account of oil and salt pollution. The Walnut River, once as fine a bass stream as could be found anywhere, and a beautiful stream, too, is now a murky oil run, and does not contain a single fish so far as I know. The Fall and Verdigris rivers are practically ruined. Both the Caney rivers are affected, and may soon be ruined for fishing." Doze (1924:31) noted "Some of the finest streams in the state have been ruined as habitat for wild life, the Walnut River is probably the most flagrant example." TABLE 3.--SEWAGE DISPOSAL FACILITIES IN SOME SOUTH-CENTRAL KANSAS COMMUNITIES.