Recently I have been involved in finding groundwater for some rather interesting rural residential projects. I have found that these projects have some interesting things in common: these are expensive homes-in the $1,000,000 to $10,000,000 range, they are built on hill top landscape positions, they will all require water to irrigate the landscaping, water for fire protection, and plentiful water for the home (including high pressure (psi) and an acceptable flow).
Another thing they have in common is that they have all budgeted somewhere between $5,000 and $10,000 for water. This number includes drilling a well, installing the pump and wiring and piping it to the house.
One last thing they have in common is that they have randomly picked a spot and drilled 600 feet (they budgeted for 300) at $10/ft and have hit nothing but rock (we call them "dusters"- yes, I've been involved with a few myself-but that's for another blog...). There's some dust from a drill rig below....!!
So, their budget is blown, everyone is freaked out and then they call the geologist. What to do?
I ask the following question: How much water do you need? The usual answer is "as much as you can get". That's the wrong answer. The accurate answer to that question will drive the amount of effort for a proper investigation and the commitment from the client and the hydrogeologist. The answer to that question requires someone to talk to the irrigation guy, the engineer designing fire protection, the architect, etc. Will there be a pool, jacuzzi, hot tub, lots of overnight guests, guest houses etc., etc..?
If I can get an accurate idea of the water consumption (you wouldn't believe how difficult it is to get an answer to that question...) then I can plan a budget for the investigation. In the photo below is an example of what 50 gallons per minute (gpm) looks like-
I have come to the conclusion that people don't plan for water- they take it for granted.-They pay close attention to the foundation, to the interior and exterior design, extraordinary amount of time discussing the details for lighting, color of the fabric, the furniture, the security systems, etc, etc. I believe it is ingrained in our culture (at least here in eastern North America)that water is free- you drill a hole and water comes out of the ground. But what I have learned is as the population increases and more land is being turned into estates, or modestly built homes for that matter, all the historical precedence goes out the window for two main reasons: (1.) people want to build on hills and consequently need their source water close by (another blog-another day) and (2.) they use way more water than usual and folks want high pressure water systems (like they have in town) and a lot of flow.
So, the geologist goes to work (if they gave up on one well...recently I was called after five wells were drilled and $25,000 had been spent-we got it on the first well but that is a story for another blog) and depending upon the size of the property, the character of the bedrock, the geometry of the fracture and joint patterns and the proximity of accessible potential water zones (PWZs)- the client could spend $5,000 to $10,000 on an investigation before drilling occurs. That number is always a surprise because the project is in full tilt (they're pouring the foundation by now....)- the budget is being violated and everybody is still freaked out because they have no water and it goes against the common idea that water should not cost money (especially paying for a geologist-after all, aren't dowsers free???).
The photo below is an exposure of an early proterozoic-age meta-gabbro, amphibolite or diabase (you choose)...the cool thing is that this rock intruded into the surrounding granite and is so brittle and full of fractures that it made this region of a project site an excellent place to start looking for water- otherwise, it's just an outcrop of rocks that looks like something out of the "Lord of the Rings", right...?
The point of this blog is to encourage my builder friends (and anyone else) to consider adding a line item for groundwater investigations for these large estate/homes. If you budget $10,000 for an investigation (0.1% of a $10M budget....i think (math goes against my grain...)) before you start drilling then everyone knows what to expect, anxiety levels are reduced and you will likely save money by limiting the number of wells drilled- the fact is the largest line item in groundwater exploration is the drilling of the wells- not what you pay the geologist.