Rainfall Update – January 2017

How are we doing so far this Water Year? The Napa County Rainfall and Stream Monitoring System, also called the ALERT System, is a network of automated rain and stream gauges installed throughout the County that provides advanced warning of potential flooding.  Although flood warnings are the primary purpose of the ALERT System, data records from the 17 rain gauges can be assessed to better understand current water conditions in the Valley. Rainfall is measured as a depth, in inches, and rainfall depths vary by location.  So far, rainfall totals for Water Year (WY) 2016-17, from October 1 through January 31, range from ~ 26 inches in the eastern hills at the south end of the Valley to 51.53 inches on Mt. St. Helena.  In order to assess rainfall across the whole Valley, we compare the total for each gauge to the annual average for that specific gauge.  Even though Mt. St. Helena has received twice as much rain so far this year than the southern end of the Valley, both locations are between 105% and 110% of average.  Altogether, the 17 ALERT rain gauges indicate that so far the Napa Valley as a whole has received 110% of its average precipitation for the year. – Paul Blank, Senior Hydrologist,

Laundry to Landscape Workshop Materials

Learn how to install a laundry to landscape greywater system in your own home during this hands-on workshop~ December 4 ~Evaluation Form: workshop attendees please take 5 minutes to let us know what you think! Workshop Materials: 2016- Powerpoint slides 2015-Powerpoint slides Greywater system user manual – template Irrigation sizing worksheet Three-way valve handle direction pictures  Soil absorption formula sheet Greywater system components diagram More Links: Learn more about requirements of no-permit greywater systems in California Learn more about Laundry-to-Landscape systems from Daily Acts Contact: Jemma Williams, or 707-252-4189 x3117 Hosts: Napa County RCD, City of Napa Water Division, County of Napa- Public...

Winterizing Your Vineyard

Winterizing your Vineyard By Charles Schembre, Vineyard Conservation Coordinator After conducting winterization/erosion control inspections on over 150 vineyard properties throughout the County, we want to take a moment to share our observations. Ground cover is one of the most critical erosion control BMP’s. Rains came early and steady this fall, promoting ideal conditions for cover crop seed germination and natural revegetation of ground cover.  We have seen very few large erosion issues in Napa County this year, most likely as a result of excellent ground cover.  A few vineyards, most of which were developed this year, experienced erosional issues from the first couple of medium size storm events because there has not been enough time for the soil to re-stabilize.    Straw wattles are often installed poorly.  Straw wattles will not function to mitigate soil erosion and concentrated flow if they are installed improperly.  We recommend that vineyard staff are educated every year about how to properly key in straw wattles.  The method below takes time, but if a straw wattle is not installed property it is useless. How to property install a straw wattle Install the wattle on contour so that it is near dead level. You can simply use a hand level in the field to achieve this. Dig small trenches across the slope on contour. The trench should be deep enough to accommodate half the thickness of the roll, roughly 6 inches deep. It is critical that the rolls are installed perpendicular to water flow. Lay the roll along the trenches fitting it snugly against the soil, making sure no caps exist between the soil and the wattle Drive 1×2 or 2×2...