Colorado Water April 2005

• Year: 2005
• Title: Colorado Water
• Author: Water Center of Colorado State University
• Description: April 2005
• Publications - Doc Type: Newsletter

Research at the Tamarack Recharge Project and a Review of the SDF Method
by Calvin Miller and Deanna Durnford
Civil Engineering Department, Colorado State University
The Colorado Division of Wild -
life (CDOW) and the Northern
Colorado Water Conservancy Dis-
trict (NCWCD) are participating in
developing an augmentation project
on the Lower South Platte River
near Crook, Colorado. The project
currently recharges groundwater at
the Tamarack State Wildlife Area
(Figures 1 and 2) during late winter
to provide increased groundwater
return flows at later times. Ten
recharge wells and three recharge
ponds are currently in operation
with plans to add additional capacity
Figure 1. Tamarack State Wildlife Area, viewing the river (among the trees) from a
groundwater recharge pond on the sand hills approximately 60 feet above and 3500
Colorado State University has had feet away from the
the opportunity to use the Tamarack
project to study recharge operations and their effects on
the aquifer and riparian water bodies. The study is being
conducted by Deanna Durnford in Civil Engineering, Bill
Sanford in Geosciences, and John Stednick in Watershed
Stewardship, along with cooperation from CDOW and
NCWCD. The ongoing study includes geophysical surveys,
aquifer pumping tests to examine stream- aquifer connection
parameters, modeling assessments, tracer tests, and several
years of water quality tracking.
As part of the Tamarack project, we reviewed the Stream
Depletion Factor (SDF) method used to assess stream
river.
depletion and accretion caused by groundwater pumping and
recharge. We compared the method in bounded aquifers
to a numerical model constructed for the Tamarack site by
CDOW. This review can be downloaded from www.hydr
ologydays.colostate.edu (Miller and Durnford 2005) and is
summarized here.
Figure 2. A project pond recharging at approximately 40 acre- feettday.
10
would be used to adjust Glover's
stream- aquifer response curve to
best match actual (as modeled)
response curves. To this end, the
aquifers along the South Platte
and Arkansas rivers in Colorado
were modeled by the USGS and
the values of this input —the SDF,
which has units of time —were
mapped (Figure 3, for example).
Use of this model - derived input
in Glover's equations is referred
to as the SDF method. The two
methods use the same mathemati-