In 1987, the Arkansas River flowed throughout its course in southwestern Kansas during much of the year. Streamflow was reduced or absent in many segments of the stream during the summer of 1988, which has been the typical case in recent years. Quantitative surveys of the ichthyofauna were conducted in 1987 and 1988 to assess the initial impacts of temporarily restored streamflow on the fishes. A total of 25 species of fishes was collected during this study, compared to 22 species reported in earlier surveys. None of the four previously reported taxa protected in Kansas was collected, but six distributional records within Kansas and increased populations of several species of fishes were documented in 1987. The Arkansas River in southwestern Kansas has experienced a general decline in streamflow as a result of consumptive water use during the past 100 years. John Martin Reservoir in southeastern Colorado, irrigation di- version dams, groundwater mining, and agricultural conservation practices have drastically altered the presettlement flow regime of the river and have had a negative impact on the fish communities in much of the river in southwestern Kansas (Cross et al., 1985). These events also have profoundly impacted the geomorphology of the Arkansas River, reducing its effective channel width in southwestern Kansas from an average of 400 m to 80 m or less (Tomelleri, 1984). In 1948, following the construction of John Martin Reservoir in south- eastern Colorado, Kansas and Colorado signed the Arkansas River Compact (K.S.A. 82a-520) to regulate the waters of the Arkansas River and provide for their control, conservation and utilization for irrigation and other ben- eficial purposes as determined by the Arkansas River Compact Adminis- tration. Each state is represented in the Administration by two water-right owners and one state official. Although the State of Kansas is entitled to 40% of the conservation pool inflow into John Martin Reservoir (K.S.A. This content downloaded from 207.46.13.85 on Tue, 23 Aug 2016 04:11:42 UTC All use subject to http://about.jstor.org/terms VOLUME 96, NUMBERS 1-2 115 82a-520), the only flow to reach Kansas from John Martin is water expressly ordered for irrigation or released to maintain adequate flood pool storage within the reservoir. The Arkansas River flowed continuously through Kansas for much of the summer of 1987 because of water released from John Martin Reservoir to allow for increased inflow from snow-melt in the Rocky Mountains. This presumably allowed populations of fishes to recolonize stream reaches that had experienced years of limited or absent flows. During this survey, data were collected from 13 sites in 1987 and 1988 to assess the initial impact of increased streamflow on the fishes of the Arkansas River from the Colorado line to Hutchinson in southcentral Kansas (Fig. 1). Data were com- pared to collections made previously in the study area as summarized by Cross et al. (1985) and the Kansas Department of Wildlife and Parks (1977). Cross et al. (1985) thoroughly discussed the condition of the Arkansas River and its ichthyofauna through 1983, and Ernsting and Cross (1987) assessed the fishes in Cheyenne Bottoms and associated streams in the Arkansas Basin. A detailed summary of this project is available in the report to the Kansas Department of Wildlife and Parks (Eberle et al., 1989).