Saturday, May 17, 2008

How full is your reservior?

Below is a link to the current reservoir levels along the Wasatch Front.

http://www.usbr.gov/uc/water/basin/tc_wf.html

Thursday, May 15, 2008

Mining Groundwater

Mining groundwater or aquifer overdraft is a serious problems in the West. Some Cities (and farming areas)in the west are already experiencing problems associated with overdraft including the need to deepen wells, land subsidence, and poorer water quality being extracted. Examples of some cites with overdraft issues are Denver, Las Vegas, and Tucson. In Utah the farming area of Beryl has experienced similar problems leading to restrictions in withdrawals and a stricter water right policy (http://www.waterrights.utah.gov/groundwater/ManagementReports/BerylEnt/berylEnterprise.asp).
Below are the definitions of overdraft and subsidence.

Overdraft
Groundwater is a highly useful and often abundant resource, however over-use or overdraft can cause major problems to human users and to the environment. The most evident problem (as far as human groundwater use is concerned) is a lowering of the water table beyond the reach of existing wells. Wells must consequently be deepened to reach the groundwater; in some places (e.g., California, Texas and India) the water table has dropped hundreds of feet due to excessive well pumping. A lowered water table may, in turn, cause other problems such as subsidence and saltwater intrusion.

Groundwater is also ecologically important. The importance of groundwater to ecosystems is often overlooked, even by freshwater biologists and ecologists. Groundwaters sustain rivers, wetlands and lakes, as well as subterranean ecosystems within karst or alluvial aquifers.

Not all ecosystems need groundwater, of course. Some terrestrial ecosystems, for example those of the open deserts and similar arid environments, exist on irregular rainfall and the moisture it delivers to the soil – supplemented by moisture in the air. While there are other terrestrial ecosystems in more hospitable environments where groundwater plays no central role, groundwater is in fact fundamental to many of the world’s major ecosystems. Water flows between groundwaters and surface waters. Most rivers, lakes and wetlands are fed by, and (at other places or times) feed groundwater – to varying degrees. Groundwater feeds soil moisture through percolation, and many terrestrial vegetation communities depend directly on either groundwater or the percolated soil moisture above the aquifer – for at least part of each year. Hypoheic zones (the mixing zone of streamwater and groundwater) and riparian zones are examples of ecotones largely or totally dependent on groundwater.

When we extract groundwater linked to a river system, we extract water from that river, even if the result is not evident for some time. And of course vice versa. Water management agencies around the world are still struggling to come to terms with this simple fact. See Kansas Geological Survey.

Subsidence
In its natural equilibrium state, the hydraulic pressure of groundwater in the pore spaces of the aquifer and the aquitard supports some of the weight of the overlying sediments. When groundwater is removed from aquifers, due to excessive pumping, pore pressures

Friday, May 2, 2008

More on Snake Valley

Below is a link to the Utah Division of Water Rights information on the Snake Valley Carbonate Aquifer project.
http://waterrights.utah.gov/meetinfo/m031505/default.htm

http://water.nv.gov/hearings/dry_cave_delamar%20hearings/ACE/Initial%20Evidentiary%20Exchange/Exhibit%201130.pdf

What an Installed Well Looks Like

Ever Wonder what the inside of a well looks like. Photo to the right is of a 10 inch stainless steel wire wrap screen at a depth of 352 feet.

The photo below is a side view of the same well. Note the build-up on the screen and the gravel-pack visiable through the screen.











Pump and Well Corrosion and Importance of Routine Maintenance

The above photo was taken of a pump that had been in a city well for about 12 years. The pump was actually running up until the week prior to failure. The city was very lucky this pump did not break in half in the well and leave part of the pump wedged in the well. This type of problem is unfortunately routine, but can be prevented by a maintenance program. Depending on use and environment when a pump is first installed in a well a set of parameters needs to be set up, monitored, and reviewed on a regular basis.