Buried Aquifers in the Brooten-Belgrade and Lake Emily Areas, West-Central Minnesota---Factors Related to Developing Water for Irrigation

Irrigation has given a substantial boost to the economy in the Brooten- Belgrade and Lake Emily areas. The surficial outwash aquifer is capable of yielding sufficient quantities of water for irrigation over half of its area; the remaining part may be supplied by deep aquifers. Buried glacial outwash and Cretaceous sand aquifers, as thick as 50 feet (15 metres) occur to depths of 300 feet (91 metres). In places, the buried aquifers are sufficiently thick and permeable to yield large quantities of water to wells. The buried aquifers are probably narrow, elongate, truncated bodies enclosed by clay till. The Precambrian surface, ranging from 190 to 350 feet (58 to 107 metres) below the land surface, is the lower limit of the buried aquifers. Water in the buried-drift aquifers is a very hard calcium magnesium bicarbonate type, suitable for irrigation needs. Water in Cretaceous aquifers, although untested, is expected to be higher in dissolved solids. Potential water problems include slow rate of recharge to buried aquifers, and head loss caused by screening of the surficial and buried aquifers in the same well, and by allowing wells to flow unabated. Another potential problem is possible pollution of the buried aquifers through the boreholes of multiaquifer wells.