WSP08741

• File Number: 8170
• Description: Arkansas Basin Water Quality Issues
• State: CO
• Basin: Arkansas
• Water Division: 2
• Date: 1/1/1993
• Author: USGS
• Title: Reconnaissance of Water Quality of Lake Henry and Lake Meredith Reservior - Crowley County - Southeastern Colorado - April-October 1987
• Water Supply Pro - Doc Type: Report/Study

0050

Table 2. Sampling-site locations and sampling dates at Lake Henry and Lake Meredith Reservoir

Location

Sampling data,
1987

Sampling site

Latllude

Longitude

Lake Henry (fig. 2)

HEW2
HNW
HSE
HEWI
HEW3

38'15'43"'
38'I6'Il""
38'15"34"
38'15'34"
38'15"51"

HNE
HSW
'HI
2HO

38'16'08"
38'15'37""
38'15"58"
38'15' 14"

103'42'33"
103'42'36"
103'42'25"
103'42'14"
103'42'53"

5-1.6-29.8-19.10-6
5-1.6-29.8-19
5-1,6-29,8-19
5-1.6-29,8-19
5-1, 6-19, 8-19

103'41'00"
103'43'05"
103'43'19"
103'43'14"

5-1,6-29,8-19
5-1, 6-29, 8-19
6-29,8-19
5-1,6-29,8-19.10-6

Lake Meredilh Reservoir (fig. 3)

M2B
MIB
M4B
MIA
MIC

38'11'40"
38'12'39"
38'10'18"
38'12'59"
38'11'58"

M2A
M2C
M3A
M3B
M4A
'Mil
'MI2

38'12'11"
38'1 r 10"
38'11'37""
38'1\"17""
38'10'18"
38'13'46"
38'10'55"

103'41'3\"'
103'40'24"
103'43'45"
103'40'25"
103'40'24"

5-1, 6-30, 8-20. 10-6
5-1, 6-30, 8-20
5-1, 6-30, 8-21
6-30. 8-20
6-30, 8-20

103'41'30"
103'41'31"
103'42'37""
103'42'37""
103'43'45"
103'41'01"
103'44'50"

6-30,8-20
6-30, 8.20
6-30.8-21
6-30.8.21
6-30. 8-21
6-30.8-21
6-30, 8-20. 10-6

Jlnnow sampling-site location.
20utflow sampling-site localion.

Waler samples for phytoplankton analysis were
collected using the water-sampling bottle from a single
deplh near the lake surface. A l-L sample was pre-
served using a 37-percent fonnaldehyde solution. The
phyloplankton count was detennined by transferring a
known part of the sample to a settling chamber and was
examined using a 200 to 1.000 power inverted micro-
scope. The chlorophyll a samples were collected from
a single depth near the lake surface and from a single
depth near the lake bottom using the water-sampling
bottle. One to two liters of a sample were filtered
through a 0.45 Ilm, cellulose-acetate filter. The filter
then was placed in a petri dish, wrapped in aluminum
foil, and frozen using dry ice. The chlorophyll a

analysis was perfonned by placing the sample in a
90-percent-aqueous acetone solution. The mixture was
steeped in the dark for 24 hours at 40C then centrifuged
for 20 min. The supernatant was decanted into stop-
pered cuvettes and was analyzed with a spectropho-
tometer (Chadwick and Associates, Littleton,
Colorado, written commun.. 1985). The phytoplank-
ton and chlorophyll a analyses were done by a private
laboratory .
For this study, two trophic-classification systems
were used for comparison to assign a relative trophic
status to Lake Henry and Lake Meredith. The first sys-
tem used was the trophic-state index (TSl) developed
by Carlson (1977), which categorizes lakes using a

INTRODUCTION 7