Evaluating the Effects of Varying Urban Irrigation Levels on Groundwater Recharge and Surface Runoff at the Parcel Scale
Image credit: AGUAbstract
Reducing urban irrigation is particularly important in arid and semi-arid cities in the United States, where landscape irrigation can account for a significant portion of household water use. However, efforts to reduce urban irrigation may unintentionally diminish streamflow, which calls for careful evaluation. In this study, we used the surface-subsurface hydrologic model ParFlow.CLM to quantify how different irrigation levels at the parcel scale can affect soil water balance components. A representative single-family parcel in the Denver metropolitan area with 36% impervious surfaces and 58% irrigated landscape was simulated under two irrigation scenarios including well-watered and deficit irrigation schedule. The well-watered scenario was defined using recommended watering schedules provided by Denver Water for Kentucky bluegrass and mature trees, and the deficit irrigation scenario applied water at 40% of the well-watered schedule. We hypothesize that deficit irrigation will reduce irrigation-induced runoff and deep drainage compared to the well-watered scenario, though the extent of these reductions is expected to depend on antecedent soil moisture and climate variability, particularly the growing season precipitation.
