EBTAG Annual Workshop and Field Trip
October 12-13, 2017

¹City of Santa Fe, NM, whschneider@ci.santa-fe.nm.us

²John Shomaker and Associates

The 2017 Santa Fe Water Reuse Feasibility Study (FS) was designed to identify the highest value use of the reclaimed water currently available from the City’s Paseo Real Water Reclamation Facility (WRF) and potential future flows from the County’s Quill WRF, while sustaining downstream flows for cultural and ecological water uses along the lower Santa Fe River. The FS determined that full consumption of its San Juan Chama Project (SJCP) water via a return flow pipeline to the Rio Grande was the highest ranked water reuse option, considering that it offers the lowest cost, provides the greatest water supply benefit through drought-resistant recycled water supplies, requires no additional treatment requirements, and utilizes Santa Fe’s investments in the BDD diversion, conveyance, and treatment systems.

The FS recognized that diverting the non-consumed portion of Santa Fe’s SJCP water will result in reductions in direct discharge from the Paseo Real Wastewater Treatment Plant to the Lower Santa Fe River (LSF River). A critical literature review was conducted to compile the existing hydrologic data along the LSF River. These data were used to develop a simplified hydrologic water budget designed to examine the primary sources (gains) and sinks (losses) of both surface and groundwater along the complex hydrogeologic system bordering the communities of La Cienega, La Cieneguilla, and La Bajada. Several studies have been conducted along these reaches and provide a central understanding of hydrogeologic conditions that influence zones of surface water infiltration to groundwater (recharge), groundwater discharge to surface water (seeps and springs), riparian zone evapo-transpirative losses and widespread diversions for potable and irrigation uses. These studies have not provided a hydrologic water balance or a numerical groundwater flow model.

This talk will present the findings of the simplified water budget and highlight some interesting observations with regards to water uses and their impacts to surface water flows and seep and spring discharges over time. Most importantly, the existing data clearly indicates there are significant data gaps in the monitoring network that impose uncertainty on the seasonal variability with the Lower Santa Fe River flows such as unmetered irrigation diversions and groundwater pumping. Recommendations are shared that illustrate the critical data gaps and ways to address collecting more hydrologic data so informed decisions can be made on sustainable water use along the LSF River.