9505

• UCREFRP Catalog Number: 9505
• Author: Cooper, D. J. and C. Severn.
• Title: Wetlands of the Escalante State Wildlife Area on the Gunnison River, Near Delta, Colorado
• USFW Year: 1994.
• USFW - Doc Type: Hydrology, Water Chemistry, Vegetation, Invertebrate Communities, and Restoration Potential.
• Copyright Material: NO

establish wells which would allow us to determine the elevation
of the water table through the sample period. Machine slotted
PVC pipe was used in the lower portion of the well and unslotted
PVC pipe in the upper part. The well was capped on the bottom
and top ends and depth to water table was determined with a well-
reader.
Surface and ground water levels were recorded regularly
during the sample period. Data on Gunnison River stage was
derived from the Whitewater gauge located downstream from the
study area. River water levels from our staff gauge 7 are used
to correlate with water levels in the wetlands. This correlation
allowed us to determine whether river and wetlands were
hydrologically connected or whether the wetlands are fed largely
by another water source. The wells and staff gauges also helped
us to determine the duration of inundation in wetlands.
Physical and chemical characteristics of water at staff
gauges (surface waters) and in wells (groundwater) were
determined in the field and laboratory. We determined pH,
conductivity, DO and temperature at sample times using a ICM
water analyzer Model 51601. For well samples, water was pumped
using a hand pump, until several well volumes had been removed
and the water ran clear. Surface and ground water samples were
collected for chemical analysis from these same stations. For
surface water and ground water collections, samples were filtered
through a 0.45 micron filter, and split into subsamples, one of
which was acidified using nitric acid, and one of which was
unacidified. Water .samples were kept cold until transfer to the
Denver Office Chemistry and Petrography Laboratory of the Bureau
of Reclamation.
The analyses were carried out under the supervision of Doug
Craft. Acidified samples were analyzed using inductively coupled
plasma spectrometry for the following metals; V, Si, Zn, Sb, Ag,
A1, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Pb, Ca, Na,
Mg, and K. In addition, Se (selenium} was determined using
graphite furnace atomic absorption spectrometry by Barringer
Laboratories in Golden, CO. Unacidified samples were analyzed
for HCO'3, SOZ'4, and Cl', along with alkalinity, lab conductivity,
lab pH, and TDS.
The water chemistry data are used for two purposes; (1) to
determine if any element occurs in concentrations that could be
of biological importance to razorback suckers, and (2) to help
identify distinct water sources feeding the wetlands. Water
quality standards published by the State of Utah are used in this
report as guidelines for elemental concentrations that exceed the
numeric criteria for aquatic life (State of Utah 1993).
Vegetation patterns were determine to allow us to analyze
the major aquatic habitats in the study area wetlands. Five
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