Update10/4/17Two years after the email exchange below laying out the concerns the county was beginning to have with a shrinking water table at the Soda Canyon Junction (and the junction of Soda Creek with the Napa River), the county staff will present their findings thus far to the Board of Supervisors on Oct 10th 2017. [Cancelled due to Oct. 8th fire] Mostly a factor of less rainfall they seem to be saying - Soda Creek just isn't transporting as much water as before. More water conservation requested.
Of course you wouldn't know that the county is interested in water conservation in the area when you consider the number of water-drawing wineries that they have approved within the study area in the last 2 years. The expansion of the Beau Vigne was approved in Sep 2016. The Sam Jasper Winery was approved in Jan 2017. The Grassi Winery was approved in Feb 2017. And now finally the last of the pending projects, Reynolds, is up for review this month. These are added to the as yet unbuilt Krupp winery approved in 2012 and the Corona Winery approved in 2013. (A map of the winery congestion is here.) The total, at 220,000 more gallons of capacity, will probably not run the wells dry, but the additional 59,600 tourists/yr and several dozen employees/day will add to the water draw as well. As a commitment to conservation in the area, adding more wineries with entertainment activities here to process grapes that are currently being processed in less water-challenged areas doesn't set a good example.
If you're not a geologist, the graphics for the presentation are a bit difficult to fathom, but the one shown above did stand out. It seems like a lot of straws in the ground!
12/7/15[Gary Margadant's email reply to Public Works Director Steve Lederer in response to information supplied about a potential groundwater deficiency in the area of Soda Canyon Road and the Silverado Trail.]
Thank you for sharing, since it is of great interest to neighbors in the immediate area and beyond. This is especially interesting to those of us who would like to explore different avenues within the information and data held by the County Administration. Your review of the well activity in the Petra Drive area is very informative. It is one avenue, a basic avenue, of groundwater monitoring and research where well activity is a very telling metric.
I am confused by one aspect of your report: The LSCE 2014 report points to groundwater elevation problems in Subarea 75, yet your note refers to well and groundwater elevations problems along Petra Drive which is in Subarea 76. Is this what you mean by the creep of the cone of depression from the MST in 75 into 76? It would be helpful to find out if the Petra Drive wells are a very local subarea or directly influenced by the MST.
Can you enlighten me on the reason for the loss of 1 or the 2 monitoring wells?
And then a question: Do you think some of the wells on Petra Drive and others near by should be fitted with Patricks' new Sonic water elevation measuring devices (real time measurements) with data transmitted to your office via a WiFi connection in the area? This might improve your understanding of the dynamics in this subarea and help with education, mitigation and conservation efforts. And some of the well owners might want them for their own edification.
Please be aware that Yeoryios Apallas owns and lives on property directly across ST from the Petra Drive corner and directly behind the SC Store. He will be receiving a distribution of this note just as Norma Tofanelli, of Dunaweal Lane.
Thanks again for sharing.
On Mon, Dec 7, 2015 Steve Lederer wrote:
I thought you might find this of interest. Please feel free to share.