Water-quality reconnaissance of the Middle and North Branch Park River watersheds, northeastern North Dakota

Abstract

In order to design a network to monitor the effects of works of improvement in the Middle and North Branch Park River watersheds, and to determine the major factors controlling water-quality conditions in the watersheds, an evaluation of sediment transport, water chemistry, and biology was conducted during the spring and early summer of 1978. Major factors controlling water quality are geology, stream gradient, ground-water seepage, and the duration of streamflow. Sediment loads originate on the Pembina Escarpment. The coarse silt and sand parts of these loads are deposited on the Lake Agassiz Plain. Transport of sediment is lowered and flow duration is increased on the Middle Branch Park River due to the presence of small dams. Observations suggest that bedload transport is a significant process, particularly in the upstream reaches. However, no quantitative bedload data were collected. During periods of low flow, analyses of water from the rivers in both watersheds show downstream increases in sodium and chloride due to ground-water seepage or the unregulated flow of wells. Diversity of benthic invertebrates indicates water-quality conditions are better on the Middle Branch Park River than on the North Branch, and are better at upstream sites than at downstream sites. A program through which the Soil Conservation Service can monitor the effects of present and future works of improvement on the watersheds was designed. The monitoring program consists of intensive sampling at four locations for sediment and water chemistry during spring and early summer runoff events and by profiles of water chemistry during summer base runoff.