Homestead Lake 



Climatic setting. The net annual precipitation balance for 

 Homestead Lake derived from the MAPS database is -25 inches, toward 

 middle of the range of evaporative intensity for sites in this 

 class. Based on analyses of evaporation pan data, this is a 

 considerable underestimate Homestead Lake's water deficit, and 

 points out the need to view the MAPS estimates only as relative 

 indicators of net site precipitation. Mean monthly precipitation 

 for the Medicine Lake climatic station shows a pronounced June 

 maximum. Annual totals for this station show apparent periodicity 

 with a 5 to 7 year cycle. Throughout the 1980s, the 3-year running 

 average remained below (often well below) the long-term average, 

 recovering in the early 1990s. In 1993 (the year before sampling) 

 precipitation exceeded the long-term average by more than 1 inch. 



Geologic setting. Homestead Lake lies along the margin of the Big 

 Muddy Creek Valley; permeable gravel aquifers (glacial and 

 preglacial?) underlie portions of the lake and are shown by ground- 

 water monitoring data to be in hydrologic communication with it. 



Hydrologic type. Homestead Lake is a modified and managed 

 impoundment with controlled inflows from Big Muddy Creek and 

 controlled outflow back to Big Muddy Creek, as well as internal 

 routing of water within management subunits of the lake. The lake 

 is hydrologically connected to regional gravel aquifers; the 

 direction of water movement between aquifers and the lake is 

 uncertain, and may be influenced by diversions of surface water 

 into Homestead Lake. Portions of Homestead Lake may have existed 

 as a seasonal water body prior to the construction of dikes and 

 diversions. 



Basin characteristics. Homestead Lake receives inflow both from 

 the natural catchment areas or Sheep Creek and Lost Creek to the 

 east and from the diversion of Big Muddy Creek. The ratio of the 

 natural western catchment to the wetland area ranks mid-range 

 within it's classification; most lake inflow comes from the Big 

 Muddy diversion, however. Management structures include dikes 

 separating lake subunits which are dependent on natural flows in 

 Sheep and Lost creeks. These were reported to be dry throughout 

 1993, the year of sampling. 



The reported capacity of Homestead Lake at "management elevation" 

 is 8216 acre-feet, with an average depth between 6 and 7 feet. 

 Large water deficits were reported for Homestead Lake throughout 

 the 1989-1993 period; at the beginning of 1993 the Homestead Lake 

 complex reportedly held only 122 acre-feet of water. High flows 

 in July of 1993 (postdating the DHES sampling) allowed the 

 diversion of an estimated 6525 acre-feet over a short period. Most 

 of this water was impounded within the northern management unit of 

 the lake, within which the WET27 site is situated. 



Water chemistry. At the time of sampling, water at the WET27 site 



