The analysis of pumping test data for a shallow riverbank aquifer affo
rded the opportunity to compare standard methods for determining hydra
ulic conductivity (K) and storativity (S) with techniques based on the
propagation of periodic fluctuations of head in the aquifer. Tidal fl
uctuations in water level at the riverbank were found to propagate app
roximately nondispersively for 200 m in the aquifer, allowing tidal ph
ase lags and amplitude attenuations in the aquifer to be estimated fro
m river levels by least-squares techniques. The least-squares attenuat
ions and phases were used to correct measured pumping test drawdowns f
or tidal influences. Standard transient analyses of the corrected draw
downs were performed, yielding values of approximately 8 to 10 m/d for
K and 0.002 for S. The low S value was taken to indicate semi-confine
d conditions. The tidal attenuation coefficients were used to determin
e the hydraulic diffusivity T/S, providing values that were integrated
over the distance from the riverbank to the relevant monitoring wells
. S values from the drawdown analyses then yielded K estimates ranging
from 3 to 7 mid. A three-dimensional finite-element simulation of the
pumping tests showed that the estimated K and S values yielded simula
ted drawdowns in reasonable agreement with field observations.