1.) WHERE DOES GROUNDWATER COME FROM?
Groundwater is the water found underground in the cracks and spaces within soil, sand and rock. It is stored in and moves gradually through geologic formations of soil, sand and rocks called aquifers.
Water is always on the move. From the time the earth was formed, it has been endlessly circulating through the hydrologic cycle. Groundwater is an important part of this continuous cycle as water evaporates, forms clouds, and returns to earth as precipitation and then the cycle starts again. Only a small percentage of the precipitated water (surface water) is able to peculate into the subsurface and contribute to a groundwater aquifer through the process of recharge.
Recharge rates will depend on various aspects such as climate, soil moisture, grain size, catchment topography ext. Once the water has joined the aquifer through recharge, it doesn’t stop there. The groundwater slowly moves through the spaces and cracks between the soil particles on its journey to lower elevations. This movement of water underground is called groundwater flow.
Eventually, after years of underground movement, the groundwater comes to a discharge area where it enters a lake or stream and becomes surface water. There, the water will once again be evaporated and begin the cycle again.
2.) HOW STRONG WILL MY BOREHOLE YIELD BE?
It will be almost impossible to determine the hydraulic yield of a borehole prior to drilling and measurement. However, by conducting a proper geohydrolic investigation of the surrounding area’s geology, topography and related geohydrological conditions it is possible to estimate a groundwater yield if certain geohydrological structures were to be penetrated.
Even if a water supplying borehole is drilled and recorded yields prove to be as predicted, SGHS highly recommend that further analysis be conducted in order to establish a sustainable yield for groundwater abstraction. This will ensure that the explored borehole is not stressed while in use, allowing long term sustainable use of this water resource.
3.) WHAT IS THE LONG TERM EFFECT OF CONTINUOUS HIGH ABSTRACTION RATES?
Groundwater availability can be compared to credit availability in your bank account. Should you withdraw cash at higher values than your monthly salary, you will soon be having account supply problems. Therefore pumping water out of the ground faster than it is replenished over the long-term causes similar problems. The volume of groundwater in storage is decreasing in many areas of South Africa in response to over abstraction and decrease in rainfall. Groundwater depletion is primarily caused by sustained groundwater pumping during periods of decreased groundwater recharge. Some of the negative effects of groundwater depletion:
-
Reduction of water in streams and lakes,
-
Reduction in groundwater table,
-
Deterioration in water quality,
-
Drying up of boreholes,
-
Drying up of water baring geological structures,
-
Decrease in borehole’s sustainable yield
Due to low rainfall values in our country, groundwater recharge volumes have decreased drastically over the last few years. As a result of this water scarcity, more people have turned to groundwater as a water supply solution. However, many groundwater users do not comply with sustainable abstraction guidelines and add to the threat of water scarcity. It is critical that each individual play their role in water preservation to help sustain water quality and availability for future users.
4.) HOW CAN I ENSURE THAT I GET THE MOST OUT OF MY UNDERLYING GROUNDWATER AQUIFER?
When dealing with resources it is always important to ensure that the quality and quantity of the product to be utilized is known. By launching a comprehensive investigation of related resource aspects, calculated decisions regarding utilization can be made. We here at SGHS pride our self as being specialists in the field of geohydraulics and associated environmental impacts. Should you inquire any assistance with groundwater related aspects, our team of experienced professionals will provide recommended action plans to assist your needs.