Dewatering: Don't Let Ground or Surface Water Sink Your Construction Project

July 18th, 2019
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At one time, the Everglades covered an area of South Florida which covered almost 11,000 square miles. While that sort of wet habitat is perfect for a wildlife ecosystem, it's not the kind of terrain that lends itself to building construction. These kinds of sites require solid, dry ground upon which to build a foundation. If groundwater or surface water is determined to be a problem at a proposed construction site, it must be remediated before the project can begin. In combination with using hydro grass for erosion control, the most effective process is known as dewatering, and it is the action of removing potentially problematic water from a construction site.

Why dewater? 

If water is found to be present at a construction site -- for example in trenches, excavations, or in areas with a high water table --it should be removed in the interest of safety. This will also prevent any future issues as the construction progresses. This is normally done through the use of pumps or evaporation before any footings are set into place. Implementing hydro grass can also be used to control soil erosion. 

As a whole, care must be taken to ensure erosion does not occur and that water is not being directed toward lakes, streams or wetlands. 

A few precautions to keep in mind 

As mentioned above, care must be used when performing the dewatering process. Here are some of the most important precautions to keep in mind when starting this project: 

Avoid pumping water directly down a slope, as this water can flow to other water sources. Preferably, water should be directed to a wooded buffer or drainage system. 

Discontinue the dewatering process if soil erosion becomes a problem. Be sure to protect the drainage channel with a hydroseeding erosion control method such as grass or vegetation to help preserve stability. 

In heavy rains, avoid dewatering as this will cause the process to move more slowly or stop altogether. 

In cases where the water has been contaminated by oil or chemicals, don't directly discharge it. Instead, run it through an oil and water separator. 

In order to move ahead with the dewatering process, additional permits and requirements may need to be acquired according to local permits. 

Knowledge of the underground water table conditions in the area are important to understand before beginning the dewatering process. 

Sump pumps are most commonly used for dewatering, but their ability to handle only small volumes of water make them somewhat limited. 

Dewatering methods 

Removing ground or surface water can be accomplished through several methods, the most simple of which is using gravity to direct water away from the site. Other methods include pumping, siphoning, or scooping using heavy equipment. Any earthen channels used for diverting water should use ditch linings for protection, and additional methods such as hydroseeding should be used to control both erosion and the speed of water flow. 

Before you start your commercial construction project, be sure to consult with hydroseed contractors who also provide dewatering services. They can advise you on the proper methods for removing water from your construction site and keeping it out -- including hydro grass, pumps, or heavy equipment -- to avoid costly problems on your site. For more information, rely on Hydrograss today.