Bums Creek 



Climatic setting. The net annual precipitation balance for the 

 Burns Creek site (estimated from the MAPS database) is -26 inches, 

 toward the less strongly evaporative end of the range shown by 

 sites in this classification. Mean monthly precipitation for the 

 Savage climatic station shows a pronounced June maximum. For most 

 of the 1980s, the 3-year running average of annual precipitation 

 remained below the long-term average for the Savage station. From 

 1990 through 1993, the 3-year average was near or above the long- 

 term average. In 1993, the year prior to sampling, precipitation 

 exceeded the long-term average by about 2 inches. 



Geologic setting. The Burns Creek drainage is incised into early 

 Tertiary sandstone, shale and clinker of the Fort Union Formation, 

 overlain in places by the Miocene Flaxville Formation or 

 equivalents. Sediments deposited in the Burns Creek valley may 

 reflect late Pleistocene glacial drainage across the Burns 

 Creek/Redwater River divide; alluvium associated with the North 

 Fork of Burns Creek appears to be unusually thick and permeable for 

 a prairie stream, and probably includes glacially transported 

 calcareous material. Ground water stored in this alluvium supports 

 a wetland complex and is drained by lower Burns Creek. 



Permeable surficial or near-surface material (Flaxville Formation 

 gravels and/or clinker) caps the upland surface in many areas; 

 where incised by Burns Creek, stratigraphically controlled ground- 

 water discharge occurs. Contact springs of this type help support 

 flows in Burns Creek and the WET12 wetland. 



Hydrologic type. The Burns Creek wetland occupies an unglaciated 

 setting influenced by periods of fluvial erosion and deposition by 

 glacial drainage. The site has at least intermittent surface water 

 inflow and outflow and may also be supported by local ground-water 

 discharge. The contributing surface drainage basin probably 

 receives contact-controlled ground water discharge in it's 

 headwaters . 



Basin Characteristics. The WET12 site is near the confluence of 

 Burns Creek and the North Fork of Burns Creek. The (estimated) 

 ratio of catchment to wetland area is toward the high end of the 

 range shown by sites classified with WET12. The North Fork of 

 Burns Creek is known locally to flow only during runoff, probably 

 due to the relative permeability and depth of the North Fork 

 alluvium. Burns Creek (mainstem) is also underlain by permeable 

 gravels which support moderately yields from a nearby irrigation 

 well. 



The Burns Creek road probably influences runoff and ground-water 

 flow paths in the vicinity of the WET12 site. 



Water chemistry. At the time of sampling, WET12 water was of a 

 moderately alkaline "oligosaline" character. Divalent cations 



