Artificial Recharge Through a Thick, Heterogeneous Unsaturated Zone

Abstract

Thick, heterogeneous unsaturated zones away from large streams in desert areas have not previously been considered suitable for artificial recharge from ponds. To test the potential for recharge in these settings, 1.3 x 10(6) m(3) of water was infiltrated through a 0.36-ha pond along Oro Grande Wash near Victorville, California, between October 2002 and January 2006. The pond overlies a regional pumping depression 117 m below land surface and is located where thickness and permeability of unsaturated deposits allowed infiltration and saturated alluvial deposits were sufficiently permeable to allow recovery of water. Because large changes in water levels caused by nearby pumping would obscure arrival of water at the water table, downward movement of water was measured using sensors in the unsaturated zone. The downward rate of water movement was initially as high as 6 m/d and decreased with depth to 0.07 m/d; the initial time to reach the water table was 3 years. After the unsaturated zone was wetted, water reached the water table in 1 year. Soluble salts and nitrate moved readily with the infiltrated water, whereas arsenic and chromium were less mobile. Numerical simulations done using the computer program TOUGH2 duplicated the downward rate of water movement, accumulation of water on perched zones, and its arrival at the water table. Assuming 10 x 10(6) m(3) of recharge annually for 20 years, a regional ground water flow model predicted water level rises of 30 m beneath the ponds, and rises exceeding 3 m in most wells serving the nearby urban area.

Coupling distributed stormwater collection and managed aquifer recharge: Field application and implications

“…This study did not quantify the fraction of infiltrated water that reached underlying aquifers, which is a challenging technical problem (Izbicki et al, 2000(Izbicki et al, , 2008Scanlon et al, 2002;Schmidt et al, 2011b). Some infiltrated water may become ET or fill unsaturated pores, never reaching the water table.…”

Spatial and Temporal Infiltration Dynamics During Managed Aquifer Recharge

“…MAR projects are often operated in arid to semiarid climates, where there is a thick vadose zone between the infiltration basin and the underlying aquifer (Heilweil et al 2007; Izbicki et al 2008). In some cases, the depth to the regional water table is tens to hundreds of meters.…”

Estimating agricultural deep drainage lag times to groundwater: application to Antelope Valley, California, USA

“…Izbicki et al . () conducted a seepage study west of Victorville on the Oro Grande River wash area to determine deep seepage lag times from ponded water. After removing the topsoil, they encountered primarily three geologic‐type units during test drilling below the ponded area: alluvium reworked from the Victorville Fan, Victorville Fan deposits and ancestral deposits of the Mojave River.…”

“…The Antelope Valley is bounded on the south and west by the San Gabriel and Tehachapi Mountains, respectively, on the north by the Rosamond and Bissell Hills and on the east by the buttes and alluvial fans of the Hi Vista area. Fremont Valley is located to the north, and just to the east is Victor Valley where field measurements of lag times (Izbicki et al ., ) were conducted. The Antelope Valley is a closed basin of approximately 346,000 ha with surface elevations that range from 700 to nearly 1100 m m.s.l.…”

“…This overestimation in lag times is well within the range of estimated recharge rates used by Izbicki et al . (). It results in pressure to solute wetting front speed ratios of 0.75–0.86 that are greater than the 0.33 suggested by Jolly et al .…”