2016 NGWA Groundwater Summit

A Proposed Approach to Sustainable Groundwater Extraction Based on Surface Water-Groundwater Interaction

Monday, April 25, 2016: 11:00 a.m.
Platte River Room (The Westin Denver Downtown)
Michael Tietze, PG, CEG, CHG , Jacobson James & Associates, Roseville, CA, United States
Bob Abrams, PhD , Consulting Hydrogeologist, San Carlos, CA
Jeff Harvey, PhD , Harvey Consulting Group, LLC, Gold River, CA

Understanding the interaction of interconnected groundwater-surface water systems is fundamental to sustainable water resources management; however, surface and groundwater management decisions must address fundamentally different issues and time frames. Surface-water management must respond to short-term climatic variations, flood control, streamflow requirements, and changes in water demand and availability. Groundwater systems typically respond to recharge and extraction over decades or longer, requiring longer-term management decisions. We present an approach to groundwater management based on management zones that recognize the physics of surface water-groundwater interaction, but honors these inherently different management requirements. Examples are provided for the Stanislaus, Tuolumne, and Colorado Rivers in California.

The amount and timing of streamflow depletion depends on pumping rate and duration, well location relative to the stream, aquifer diffusivity, streambed conductance, and vertical flow impedance within the aquifer system. These principles were used to develop proposed groundwater management zones around aquifer-connected streams by simulating extraction from theoretical wells at various depths and distances from the streams, under a range of stream and aquifer conditions. Simulations were carried out using STRMDEPL08, an analytical streamflow-depletion model developed by the USGS, and validated using existing numerical groundwater flow models constructed using the USGS MODFLOW code. Simulated surface water depletion by shallow wells near streams closely mimics applied pumping rates and timing, which supports groundwater management in tandem with surface water as is currently done in California for pumping from a “known and definite channel.” Pumping from greater distance or depth causes an attenuated hydrologic response in both amplitude and time. Groundwater management zones are thus proposed based on distance to the affected stream, depth of the well’s screen interval, and timing and duration of predicted streamflow depletion, considering the amount of seasonal and long-term streamflow depletion that is tolerable under existing ecological and water rights requirements.

Michael Tietze, PG, CEG, CHG, Jacobson James & Associates, Roseville, CA, United States
Mike Tietze has 30 years of experience managing groundwater resources, permitting, and environmental projects throughout California and the western U.S., primarily for the energy and municipal sector. His work has focused on water management studies, water supply investigations, and impact analysis for projects in arid, agricultural, and overdrafted basins.

Bob Abrams, PhD, Consulting Hydrogeologist, San Carlos, CA
Bob Abrams has more than 15 years of experience in the quantitative analysis of groundwater and vadose zone systems. He has addressed issues of water quality, agrochemical impacts, groundwater sustainability, enhanced recharge and aquifer storage, and water supply development.

Jeff Harvey, PhD, Harvey Consulting Group, LLC, Gold River, CA
Jeff Harvey has worked in environmental compliance for power, water, and mining projects in California for more than 25 years. He has expertise in the requirements of CEQA, NEPA, and related laws and regulations pertaining to water supply, water quality, land use planning, and natural resources conservation and management.