The Minor area is in the north-central part of North Dakota and includes part of the Souris River valley. The region is covered by glacial drift of late Wisconsin age except ill small areas where the Fort Union Formation of Tertiary age crops out. Thickness of the drift is controlled .by the topography of the bedrock. In places the drift is more than 450 feet thick, but it averages about 100 feet thick.
Water from the Fort Union Formation is soft and is of sodium bicarbonate type that is undesirable for many uses. Wells in the formation produce only a few gallons per minute.
Six glacial aquifers were studied in the report area, but detailed work was limited to the Minor aquifer. The Sundre buried-channel and the lower Souris aquifers contain large quantities of hard water of good chemical quality, but little is known of their hydraulic characteristics owing ,to lack of development. The North Hill and South Hill aquifers generally pro-tide small quantities of hard water that may be high in iron and sodium. The northwest buried-channel aquifer has a high content of iron and chloride. Locally as much as 1,000 gallons per minute may be pumped from it.
The Minor aquifer is a thick deposit of sand and gravel confined to the Souris River valley. The water level has declined more than 70 feet since the first municipal well began pumping in 1916. In .some places the water level in the aquifer declined more than 20 feet during 1961-1963. The rapid decline in water level indicates that a serious water shortage may arise in the near future unless counter measures are taken to prevent it.
The Minor aquifer is under both artesian and water-table conditions. In places the transmissibility exceeds 250,000 gallons per day per foot. In 1963, 13 municipal wells pumiced an average of nearly 4 million gallons per day from the aquifer. Some wells produce as much as 1,000 gallons per minute.
The Minor aquifer receives most of its recharge from the buried glaciofluvial deposits and from the Souris River. Natural recharge probably averaged about 3 million gallons per day. About 56,000 acre-feet of water available to wells was in storage in 1963.
Artificial recharge could be used to counteract the rapid decline in water levels. Several feasible artificial recharge sites are in the western part of Minor, where highly permeable sand and gravel crop out.
Additional Publication Details
USGS Numbered Series
Geohydrology of the Souris River Valley in the vicinity of Minot, North Dakota