Variably-saturated groundwater modeling for optimizing managed aquifer recharge using trench infiltration

Hydrological Processes
By: , and 

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Abstract

Spreading-basin methods have resulted in more than 130 million cubic meters of recharge to the unconfined Navajo Sandstone of southern Utah in the past decade, but infiltration rates have slowed in recent years because of reduced hydraulic gradients and clogging. Trench infiltration is a promising alternative technique for increasing recharge and minimizing evaporation. This paper uses a variably saturated flow model to further investigate the relative importance of the following variables on rates of trench infiltration to unconfined aquifers: saturated hydraulic conductivity, trench spacing and dimensions, initial water-table depth, alternate wet/dry periods, and number of parallel trenches. Modeling results showed (1) increased infiltration with higher hydraulic conductivity, deeper initial water tables, and larger spacing between parallel trenches, (2) deeper or wider trenches do not substantially increase infiltration, (3) alternating wet/dry periods result in less overall infiltration than keeping the trenches continuously full, and (4) larger numbers of parallel trenches within a fixed area increases infiltration but with a diminishing effect as trench spacing becomes tighter. An empirical equation for estimating expected trench infiltration rates as a function of hydraulic conductivity and initial water-table depth was derived and can be used for evaluating feasibility of trench infiltration in other hydrogeologic settings

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Variably-saturated groundwater modeling for optimizing managed aquifer recharge using trench infiltration
Series title Hydrological Processes
DOI 10.1002/hyp.10413
Volume 29
Issue 3
Year Published 2015
Language English
Publisher Wiley
Contributing office(s) Utah Water Science Center
Description 10 p.
First page 310
Last page 319
Country United States
State Utah
Online Only (Y/N) N
Additional Online Files (Y/N) N