Wellpoint system is a solution that we used successfully in a wind farm with serious drainage problems.
The soil was made of silty sands, with a very high water table level due to a river nearby.
The system consists of several interconnected wells spaced along a trench. All of them are connected to a common header, and the water is moved thanks to one or several submersible pumps.
Our depth was about 2.5 meters, but the system works with depth up to 7 meters. With this solution, a dry bottom of excavation was obtained and the foundation was successfully completed.