Sacramento Branch Meeting-Joint GRA and AEG Holiday Meeting! Holiday Mixer and Raffle!

The Sacramento Branch is pleased to present:

Technical Consensus and Multi-Party Sustainability Planning, Westside Groundwater Basin

John Fio, Hydrologist
HydroFocus, Inc.


The Westside Groundwater Basin located in San Francisco and northern San Mateo counties has been a reliable source of drinking and irrigation water for over 100 years. The basin also includes Lake Merced, which is a surface expression of the groundwater table and significant recreational and natural resource. For the past 20 years, coordinated groundwater management among multiple agencies and stakeholders exemplifies successful sustainability planning for water supply and groundwater dependent ecosystems, and demonstrates effective use of best management practices, monitoring, water budgets, conceptual models and groundwater-flow modeling.

The Westside Basin Groundwater-Flow Model serves as an important consensus building tool and an overarching platform for directing data collection and estimating water budgets for management efforts.  HydroFocus developed and documented the USGS MODFLOW model to maximize accessibility and facilitate review by multiple interested parties, stakeholders and technical experts.  Stakeholder involvement has promoted the exchange of new data and creative insights about recommended model use, data collection, and model improvements. The peer review process has also effectively identified model limitations.

In 2002, interested agencies, stakeholder groups and individuals provided input for initial model development.  The primary objectives included data assembly, monitoring assessment, and preliminary quantification of storage responses to changes in basin inflows and outflows. Updated versions of the model have been employed to estimate water budgets, identify data needs, refine monitoring, and plan groundwater development and conjunctive use projects.

Since 2002, the model has been updated three times to increase reliability. The first update reflected new borehole data, water level monitoring, aquifer tests, and pilot conjunctive use project results.  Subsequent updates incorporated new insights from multiple well cluster sites which provided detailed information on the depth distribution of groundwater levels in shallow, intermediate, and deep basin water-bearing zones. Quantitative comparisons of the four model versions provide practical insight into the relationships between expanded data collection, model improvement, and the reliability of model-calculated water budgets. The recent determination of groundwater age using tritium and helium, and water sources using water isotopes (oxygen-18 and deuterium) provided important insights about the age and source of shallow zone recharge which shall be incorporated into future model updates.


John Fio is Vice President and a founding principal of HydroFocus, Inc.  His experience includes almost ten years of research and project leadership with the U.S. Geological Survey, and more than 20 years in private consulting. His tool box includes numerical flow and transport modeling, geochemical modeling, and chemical, isotopic, and age-dating techniques.


About Confluence Environmental, Inc.:

Confluence Environmental, Inc. is committed to providing the highest level of sampling, technical field services and construction support at competitive rates. Our field experience, superior equipment and expertise ensure that jobs run safely, smoothly, and efficiently. Complicated sites with intensive protocol and coordination needs are our specialty. We offer support in all aspects of field management from performing general maintenance to sampling, installation and demo. While groundwater monitoring and sampling has been our premier service we some of our additional service features include: pressure grouting, concrete coring, concrete flag or sidewalk replacement and quality hot asphalt repair. Based project demands we can complement your company's existing field staff, or operate independently. Confluence Environmental is a CPUC certified WBE and California State Certified Small Business. We maintain C-8, C-12 and C-57 Licenses with HAZ - Hazardous Substance Removal Certification and is ISNetworld® and PICS certified. We provide services throughout California and the greater Western States.


All Proceeds to Benefit Science Students

The GRA Sacramento Branch has a history of supporting university-level science students. Our Scholastic Sponsorship Program is an opportunity to publicize your business while contributing toward a good cause. The cost is minimal; if interested, please contact Linda Bond at (530) 757-1500 or


Don’t forget that we are holding the traditional holiday RAFFLE!!  One ticket will be included with each registration.  Additional tickets are for sale at:

$1 each for up to 5 tickets

$5 for 6 tickets

$10 for 13 tickets

Please bring prizes that geology and engineer-types will love (rocks, minerals, books, beer, wine…).  All proceeds will benefit geology students in the local area, so be generous and help support our next generation of geologists.


Social Hour - 5:30-6:30 p.m.
Announcements & Dinner - 6:30-7:30 p.m.
Presentation - 7:30-8:30 p.m.
Raffle - 8:30 p.m.
Usual great food, including two meat entrées, salad, rice, potatoes, vegetable and Iced Tea. A No-host beer and wine bar will be available.


Members: $33.00
Non-Members: $38.00
Students: $10.00

  • If you register after Noon on Monday, December 11th, or walk-in, a $3.00 surcharge will be added to the meeting cost.
  • Cancellations must be made by Noon on Monday, December 11th.

If you have questions about the meeting, please telephone Rodney Fricke at 916-407-8539 or email him at  For questions about Sacramento Branch in general, including submittal of your ideas and/or desires for future presentations, please telephone Linda Bond at (530) 757-1500 or email her at


January 10th: Noah Heller with BESST, Inc., "Treatment Avoidance" Through Well Modification - Saving Money for California Rate and Tax Payers

February 13th (Tuesday): Jeffrey Mount, Public Policy Institute of California, David Keith Todd Lecturer, The Consequences of Groundwater Sustainability in California



Wed, Dec. 13, 2017
5:30 p.m. - 8:30 p.m.

Event has ended


Aviators Restaurant
6151 Freeport Blvd
Sacramento, California 95822

Aviator's Restaurant at the Sacramento Executive Airport
6151 Freeport Blvd., Sacramento, CA
Aviator's Restaurant is located within the aircraft Terminal Building.
Plenty of free parking.