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<br />major shareholder in Lake Henry (about 77 percent),
<br />Lake Meredith (about 52 percent), and the Colorado
<br />Canal (about 56 percent). The remaining shares are
<br />owned by other entities.
<br />Water entering Lake Henry is diverted from the
<br />Arkansas River by the Colorado Canal about 30 mi
<br />west of Ordway. Water is released from Lake Henry
<br />into the Sugar City Lateral for irrigation use and also
<br />can be diverted from this lateral into the Lake Meredith
<br />inlet for storage in Lake Meredith. Lake Meredith also
<br />receives water from Bob Creek. Water is stored in
<br />Lake Meredith for exchange with the Holbrook Canal,
<br />the Fort Lyon Storage Canal. or the Arkansas River
<br />(fig. I). Water from the Lake Meredith outlet can be
<br />discharged into both canals. In order to make an
<br />exchange, water is released from Lake Meredith and is
<br />delivered to the Holbrook Canal, to the Fort Lyon Stor-
<br />age Canal, or to the Arkansas River. The same quantity
<br />of water then is diverted from the Arkansas River into
<br />the Colorado Canal (Abbott, 1985).
<br />Lake Henry and Lake Meredith are shallow.
<br />Duri ng the sampling period, the largest depths mea-
<br />sured at the time of collection of water samples were
<br />10ft in Lake Henry and 15ft in Lake Meredith. A large
<br />fluctuation in content occurred in both lakes among the
<br />sampling dates-from 7,640 to 2,310 acre-ft in Lake
<br />Henry and from 41,380 to 16,920 acre-ft in Lake
<br />Meredith. The contents of each fake on the sampling
<br />dates are listed in table I.
<br />Lake Henry and Lake Meredith are classified by
<br />the Colorado Department of Health (1987) for class I
<br />recreation, class I warm-water aquatic life, and agri-
<br />culture. Class I recreation is described as water suit-
<br />able for primary contact where prolonged contact with
<br />the body occurs or where small quantities of water may
<br />be ingested during recreational activities. Class 1
<br />warm-water aquatic life is described as water suitable
<br />
<br />Table 1. Contents of Lake Henry and Lake Meredith for
<br />each sampling date
<br />
<br />Lake
<br />
<br />Sampling dale,
<br />1987
<br />May I
<br />June 29
<br />August 19
<br />October 6
<br />May I
<br />June 3D
<br />August 20. 2t
<br />October 6
<br />
<br />Contents
<br />(acre-reet)
<br />7,640
<br />6.490
<br />3,560
<br />2.310
<br />38.290
<br />41,380
<br />23,210
<br />16,920
<br />
<br />Henry
<br />
<br />Meredith
<br />
<br />for the protection and maintenance of aquatic-life
<br />forms where the water temperature frequently exceeds
<br />20oC. The agriculture classification is described as
<br />water suitable for irrigation of crops and water that is
<br />not hazardous as drinking water for livestock (Colo-
<br />rado Department of Health, 1987).
<br />
<br />Methods of Investigation
<br />
<br />On April 29-30, 1987, a preliminary reconnais-
<br />sance of Lake Henry and Lake Meredith was made to
<br />select sampling sites (figs. 2 and 3). A depth sounder
<br />was used to determine the bathymetry of each lake.
<br />Seven sampling sites in Lake Henry and 10 sampling
<br />sites in Lake Meredith were selected. Sampling sites
<br />on the inflows of each lake and the outflow of Lake
<br />Henry also were selected. The outflow of Lake
<br />Meredith was not measured because water was not
<br />being released on the sampling dates. Each lake was
<br />sampled in May, June. August, and October 1987
<br />(table 2).
<br />
<br />Onsite measurements of water temperature, dis-
<br />solved oxygen, pH, specific conductance, and light
<br />transparency were made at all sites in each lake on the
<br />sampling dates. Water temperature, dissolved oxygen,
<br />pH, and specific conductance were measured at 3-ft
<br />intervals from the surface to the bottom of the lake
<br />using a multiparameter meter. Light transparency was
<br />approximated by using a Secchi disk-a white. flat, cir-
<br />cular disk about 8 in. in diameter. The light-transpar-
<br />ency measurements were made by recording the depth
<br />to the nearest 0.5 ft at which the Secchi disk disap-
<br />peared from view. The depth approximated by the use
<br />of the Secchi disk is referred to as the Secchi-disk
<br />depth. Water temperature, dissolved oxygen, pH, and
<br />specific conductance also were measured at the inflows
<br />of each lake and the outflow of Lake Henry (table 2).
<br />
<br />Water samples were collected near the center of
<br />each lake for laboratory analysis of chemical and bio-
<br />logical constituents. Samples for chemical analysis
<br />were collected near the lake surface and near the lake
<br />bottom using a 4-L, 2-ft-long, polyethylene, water-
<br />sampling bottle. In addition, water samples were col-
<br />lected near the inflows and outflow of Lake Meredith
<br />for analyses of concentrations of total nutrients,
<br />selected total trace elements, and chlorophyll a. Proce-
<br />dures used for collection, preservation, and analysis of
<br />water samples are discussed in Brown and others
<br />(1970), Fishman and Friedman (1985), and Britton and
<br />Greeson (1989). Chemical constituents were analyzed
<br />at the U.S. Geological Survey National Water-Quality
<br />Laboratory in Arvada. Colorado.
<br />
<br />4 Reconnaissance of Water Quality of Lake Henry and lake Meredith Reservoir, Crowley County, Southeastern
<br />Colorado, Aprll.October 1987
<br />
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