Water and Country Property: How many Gallons per Minute does your Well Produce?

filed under: Country Property posted on May 6th, 2012

As part of our Wine Country and Horse Country Property Series we have been looking at water. One of the most important items to consider when evaluating a country property is how much water does the well produce? How many gallons per minute (GPM)?

Sonoma County’s minimum requirement is currently ONE gallon per minute to build a single-family dwelling. Typically when a well is evaluated as part of the pre-purchase inspection, the tap is opened and run for a minimum of two hours to draw down the well and see how quickly it replenishes. When you think about it, one gallon per minute of water is actually a lot of water but I would be very hesitant to recommend a purchase of a property with this level of production unless you also had storage to accumulate some of that water for drawing down later for irrigation and home use. I know of one property in Sebatopol on acreage that only had a 1 GPM well. The builder decided to rent it out to a family of five for a year to prove that it was viable. Still, they had drought tolerant, minimal landscaping and it was a push. It is really not practical to to any extensive irrigation at this level, let along think about vineyards, orchards or livestock.

A property with 2-5 GPM will likely need to have storage as well. As you go over 10 GPM (my property is blessed with 27 GPM) then the storage requirements drop. It can literally vary from hill to hill so it is important that your realtor have some familiarity with water issues in the area you are considering before you seriously pursue a particular property. When it comes to evaluating the water system on a property you are in escrow on, then the experts come in to do their full-blown testing. That can run about $400 or $500 dollars or more depending on the extent of the exam. For example, when you evaluate water quality for a potential vineyard, the water testing is more extensive and more expensive.

In water scarce areas, Sonoma County has more extensive flow testing and requires it be done at the end of the dry season. The time of the year can impact the flow rate, and at the end of the dry season a well flow test will give you a more adequate picture of the toughest conditions your well will face. This is a link to the county’s requirements for water scarce areas.

You can find out the groundwater area your prospective country property is located in my post about groundwater classification here.

posted by Pam Buda // Comments Off on Water and Country Property: How many Gallons per Minute does your Well Produce?