Rector Reservoir is Drying Up (update)
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Bill Hocker | Feb 26, 2018

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Update 2/26/18
The subsequent article in the Yountville Sun notes that siltation has decreased the volume of Rector Reservoir from 4500 to 3100 acre feet in the last 70 years. Which means that in addition to the potential loss of spring water into the reservoir from groundwater pumping for vineyards, that siltation from the creation of those vineyards since the 1980's (1500 acres) is reducing the capacity of the reservoir and the water available for use. Which also means that it takes an ever diminishing amount of water to fill the reservoir each year, giving a false sense that agricultural development and a warming climate have not had an impact on water levels. The siltation shown in the photo in this post from last year is from a vineyard re-planting a bit up from the road crossing.

Again Rector Reservoir, given the high ratio of vineyard acerage to watershed area is proving to be an interesting indicator of the potential effects of ongoing vineyard development in the other watersheds of the county. This story just keeps getting more interesting.

NVR 2/21/18: As Yountville reservoir falls, state studies supply – and possible water purchases from Napa

An article in this week's Yountville Sun was pretty arresting: "Rector Dam water could Run out in Aug". I was both surprised, and, given concerns over climate change and the enormous amount of ground water being sucked out of the Rector watershed for vineyard development in the last 25 years, not surprised.

The prospect of Rector going dry, if indeed that is the case, will raise a couple of questions: What impact is vineyard development in the watersheds going to have on water availability, both surface and groundwater, as climate change happens. When it comes to apportioning water for residents, agriculture or tourism who gets preference?

Rector water level and watershed development

The Rector watershed is the most heavily cultivated of Napa's 5 watersheds with approximately 21% of its surface area in vines. The amount of ground water being pumped must be enormous. Does that pumping result in lower levels in the Rector Reservoir? Ground water and surface water are an integrated system, each impacting the other. The Rector Reservoir is over 1000' below the vineyards on the watershed and is undoubtedly augmented with the water of numerous springs from the sides of its steep canyon. While vineyard developer's consultants may try to make a case otherwise, the decreasing water table created by groundwater pumping undoubtedly contributes to a reduction in water reaching the reservoir. The water table is falling on the Rector plateau - I know that from changes in the water level of our spring-fed pond which no longer overflows into the canyon each winter and now dries up completely in the summer. Whether from less rainfall or from increased ground water pumping is impossible to say. Both have been happening since we moved there 25 years ago.

I have always felt that the Rector watershed, given the acerage of vines that cover it, should be a test case for all of Napa's watersheds, illustrating how continued development of the watershed for vineyard use will ultimately impact the water all Napans rely on. The fact that it is the first water supply experiencing the possibility of drying up, should be of concern to all.

Rector water level and tourism development

On the same page of the Yountville Sun, there is an article about a proposed rate hike for water and sewer services in the town. (The city of Yountville gets its water from Rector Reservoir, under contract from the State Dept of Veterans Affairs which owns it and the Veterans Home.) In the article and in LTE's in the same issue, there is a great deal of consternation among city residents that they should be asked to pay for the infrastructure costs of water and sewer systems when, as they rightly surmise, it is the continual increase in the tourism population that necessitates the upgrades. The resident population of Yountville has decreased slightly in the last 30 years from 3200 to 3000. By contrast, the hotel population, 460 rooms or so, has increased the daily population by 900 people, almost all since 1990. In addition, the day-tripper population has grown considerably as the valley has exploded into a good-life mass-tourism destination. The amount of water used and sewage generated has increased proportionately. In fact, high-end hotels and restaurants are high water users compared to residences. Residents are right to ask why they should pay. One frustrated resident recommended raising the TOT instead, stoking a huffy response from Visit Napa Valley's Clay Gregory, Napa's official tourism promoter, saying that the costs are fairly prorated based on water use. Which, of course, still means that residents are paying a portion of the costs necessary to accommodate the tourist population.

The problems of a drying Rector Reservoir highlight the tradeoffs that all Napans may eventually have to make between residents, growers, wine makers and tourists (as well as fish). In reading an article on the drying up of Cape Town's water one comment struck me: "Letting a well-heeled German tourist use some [water] to rinse beach sand off his bottom probably does more good for the economy than spraying it on a wheat field." At what point will the TOT be prioritized over the vines on the basis of the most profit for the available water? Perhaps not soon. But tourism is definitely a more profitable use of land than agriculture, and a water shortage will only accelerate the transfer from an agriculture to tourism economy. At some point, as I tried to bring out in my bit on Bali's water shortage, tourism and agriculture will be on a collision course over water as they are now over the county’s economic soul.

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