If you have a major excavation project on the books but haven't been involved in this type of activity before, then you will be looking at the practicality of the job and identifying what you will find below. Of course, you'll want to know whether there are any utility lines or other hardware through the site, but you also need to be aware of underground water. Even though you may live in an arid part of the country, it's likely that there is groundwater to a certain extent. So that you can continue your excavation work in stable and relatively dry conditions, you need to introduce some specialist water pumps to help you. What options do you have with this process, which is often known as dewatering?
Taking Everything into Account
Much is going to depend on the permeability of the soil and the extent of the groundwater in place. You will also need to consider just how far down you will excavate, as this will affect the capability of the pumps that you bring in.
In the simplest of cases, you will be able to extract the water as it enters the excavation, so long as the volume is not too great. You will need to dig special pits (called sumps) and use several pumps that are designed to extract a certain amount of solids with the fluid. If you don't have to go down too far, this is an ideal solution.
If you will be digging a long way, then you may need a deep well solution using electrically powered pumps that are submersible. You will need to bore down in several locations around the perimeter and may also have to place some pumps in the middle of the excavation itself. This will enable you to keep the groundwater levels manageable.
A third method is known as "well pointing." A variety of shallow wells are connected to a piping system and special suction pumps are used to extract the liquid. This is best when the excavation is not too deep, but you can always add additional well points with increasing depth.
If these methods do not fit the bill, you may have to introduce specialist alternatives which work in low permeability situations. For this, you can use a series of ejector wells which create high-pressure at the base of each well and initiate a vacuum that drains the water through the various levels.
Your Best Option
Once you've determined what you've got to work with, have a word with your pump supplier so that you get the best solution to keep you dry.