Field scale quantification indicates potential for variability in return flows from flood irrigation in the high altitude western US

Beneficial ‘inefficiencies’ of western ranching: Flood-irrigated hay production sustains wetland systems by mimicking historic hydrologic processes

“…Recent work by Donnelly et al (in press) found that core greater sandhill crane (Antigone canadensis tabida) breeding areas overlaid 93% of grass-hay production in the Intermountain West, accounting for more than 60% of temporary wetland habitats supporting birds. Moreover, healthy riparian groundwater systems sustained by grass-hay production are supportive of drought-tolerant phreatophytic plant communities (Gordon et al, 2020) that bolster vegetative productivity in later summer, providing wildlife with predictable foraging opportunities during periods of seasonal drought when most upland vegetation is desiccated (Silverman et al, 2019).…”

“…More recent work examining grass-hay production in the Upper Green River Basin, Wyoming, attributed over two-thirds of flood-irrigation water use to ES, including groundwater recharge, late summer in stream discharge, and consumption (i.e., evapotranspiration) supporting native riparian vegetation. (Gordon et al, 2020). We acknowledge that local ecological complexities can influence relationships between irrigation practices and ES benefits through variance in the mechanistic drivers underlying hydrologic function (i.e., geology, climate, and land use).…”

“…Recent work by Donnelly et al (in press) found that core greater sandhill crane ( Antigone canadensis tabida ) breeding areas overlaid 93% of grass-hay production in the Intermountain West, accounting for more than 60% of temporary wetland habitats supporting birds. Moreover, healthy riparian groundwater systems sustained by grass-hay production are supportive of drought-tolerant phreatophytic plant communities (Gordon et al, 2020) that bolster vegetative productivity in later summer, providing wildlife with predictable foraging opportunities during periods of seasonal drought when most upland vegetation is desiccated (Silverman et al, 2019). Studies examining greater sage-grouse (Centrocercus urophasianus) identify drought tolerance in grass-hay agricultural systems as a central habitat component in the bird’s life history that sustains populations during periods of prolonged drought when foraging resources are otherwise scarce (Donnelly et al, 2018).…”

“…Maintaining grass-hay ES will be predicated partly on continued water use equity among agriculture and ecological demands. Aquatic ecosystems can benefit from irrigation-induced groundwater discharge to seasonally bolster stream flows, but excessive agricultural diversions may dampen benefits if flows fall below the levels needed to sustain fish and invertebrate communities (Gordon et al, 2020). For example, Robertson and Dey ( 2009) have linked excessive grass-hay irrigation diversions to depleted stream flows and declining aquatic productivity in Upper Green River, Wyoming.…”

Can We Use the Water Budget to Infer Upland Catchment Behavior? The Role of Data Set Error Estimation and Interbasin Groundwater Flow

“…Here too, there is potential value in microwave‐based soil moisture retrievals (Crow et al., 2017), which could serve as a down‐scaling tool. Other approaches, such as hydro‐geophysical characterization (Gordon et al., 2020; Schmidt & Rempe, 2020; Smith et al., 2017), or some combination of the above in combination with the water budget (Hahm, Dralle et al., 2019; Hahm, Rempe et al., 2019) may also be helpful in improving our understanding of upland groundwater resources. At larger scales, however, physically based frameworks like the one put forward by Fan (2019) can help to improve and refine our understanding of the characteristics that promote interbasin groundwater import or export beyond those illustrated here.…”