Lieutenant Colonel Derby dealt with one of the most heated controversies the District ever faced. In 1905, Duluth commercial interests, Leech Lake Indians, Aitkin area farmers, the railroads, and lakeshore owners called for the abolishment of the headwaters reservoirs. They claimed the Government dams only assisted millers, loggers, and power companies in Minneapolis. The Board of Engineers held public hearings that found the District operated the reservoirs in the best interests of navigation, in accordance with congressional authorization. Derby also completed the Pokegama dam.