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DEVILS HOLE WORKSHOP FIELD TRIP IMPRESSIONS
IF YOU ARE HERE ONLY FOR THE PICTURES, Scroll to the links at the bottom of the page.
It was the Fourth of June, 2004. It was 108 Fahrenheit in Las Vegas. My watch showed the same temperature at Devils Hole, Nevada that afternoon. Drink, drink, drink!
It was the third day of a 3-day workshop, the tenth annual, where people from all over who do scientific work on the Death Valley regional groundwater system get together for what is called the Devils Hole Workshop. This was the tenth such workshop. It was held at the Community Center in Pahrump, Nevada. "Pah" in Native American language means water, so Pahrump has water that comes to the surface in some places.
I gave a little presentation, as did many others, but the highlight of the meeting was the field trip up onto the western flank of the Spring Range to see a recharge area and down close to Death Valley to see Devils Hole, part of a sizable discharge area.
I have described this area before, and you can see my pictures of Devils Hole and its surroundings at this page (click here). But, this time I took more/better(?) pictures. See new links below.ONCE MORE ---IF YOU ARE HERE ONLY FOR THE PICTURES, Scroll to the links at the bottom of the page.
So what is this recharge and discharge stuff all about? Groundwater is the life blood of rural Nevada. Put down a well, insert a pipe and a pump, turn on the pump, and voila! Water in tap and tub and toilet!
But what if many people pump in the same area? Then water levels drop, and hopefully your well does not have to be deepended or replaced to suck water from a lower level. In extreme cases, land actually sinks because removing water from beneath it removes an important source of pressure that helps maintain structure: no pressure and open spaces collapse and land sinks.
None of these problems occur when there is enough new water coming into the ground every year to replenish what is taken out. Then water levels in wells don't drop and land does not subside. That incoming water from nature (or from a canal put in for the purpose, in some areas of the country) is called recharge. It is like recharging a battery by putting in electrons to replace the ones removed during use of the device the battery is installed in.
So recharge is what goes into the groundwater system. If wells do not draw down the water levels permanently (draw-down in summer and replenishment in winter is OK, in other words), it is said that they are not pulling out more than the annual yield of the groundwater system. The annual yield is how much can be taken out every year without dropping the water level permanently.
Then what is discharge? It is the water that naturally exits the groundwater sytem, at springs, seeps, and playas (salty, dry lake bottoms) in the arid west, and into streams, rivers and lakes as "base flow" (meaning flow coming out of the ground rather than from rainfall/snowmelt runoff on the surface) in parts of the country where streams flow and lakes sit. Streams flow and lakes sit around in the arid west also.
A playa is a place where, usually, there is rock near the surface that does not readily transmit water, forcing flow that was deeper up and over it. When it gets too near the surface, the sun's direct or transmitted heat evaporates it and leaves salt crusts. There are also playas that are simply places where surface flows come together to make a lake that is dry most of the year, so that every rainfall leaves behind silica and salt, making for a dry lake. Death Valley and the valleys that surround it have sizable playas, and also many seeps and springs feeding those playes with underground flow. The link given above, at the end, has pictures of such a playa in Amargosa Valley that receives part of its water from the Devils Hole/Ash meadows area.
Playas are visually easy to find and explain: they tend to represent the lowest portions of each valley, so it is obvious that when there is a big strom event, water will collect there and sit and evaporate. But why so many springs and seeps? Not intuitively obvious, except maybe in Death Valley itself which lies so low (much of its central and southern base sits below sea level) as to actually intercept what is pretty deep groundwater flow in the surrounding, higher valleys.
But what about the Tecopa area, where (elsewhere on this site) I have shown pictures, see the link given above as well as this one) of the flows that come from springs and the vegetation that comes with seeps? And what about the discharge area that Devils Hole sits in? All these areas sit about 2100 feet or so above sea level. Maybe the rocks that water flows through are faulted and consequently fractured to allow pressure built up in higher areas to bleed off onto the surface in these locations?
This is what Artesian wells are all about, and there is one of those in southern Amargosa Valley, near Death Valley Junction, just in front of Franklin Lake Playa. It has flowed for years, and flows because the water in the confined area into which it tapped is under some pressure from being recharged at a higher elevation and trapped by layers of rock that do not allow much bleed-through, creating pressure. A few miles south and the lower rock layer comes near the surface, the upper rock layer is all broken up, and water evaporates making for a salt-indurated badland. I have pictures of that badland on this website, of course, see the first link in the text above, or simply click here for the same link.
So, now we know the language. Let's go see some recharge in progress, as well as some discharge!
1. Carpenter Canyon, lower portion
2. Carpenter Canyon, middle portion
3. Carpenter Canyon, upper portion
4. Devils Hole
5. Ash Meadows, Crystal Springs and Lakes
6. Ash Meadows, Point of Rocks
7. Stewart Valley and back to Pahrump Valley
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