Case Study - Brenhaven

The property behind this residence is about three feet higher than this backyard, and both surface and subsurface water are flowing onto this property. The pool is being stained by the iron that is in the spring water and the grass in the small yard stays soggy after a rain. This residence is located in southwest Arlington, where springs can be very active at times.

Most of the trench has been excavated and the brown, iron-rich water can be seen in the bottom. A combination French drain and area drain will be used to solve this drainage problem. The French drain will be installed to collect subsurface flow before it can migrate to the side of the pool and cause the horrible brown stains on the wall of the pool and deck steps. A surface system consisting of catch basins attached to solid pipe will be installed near the surface to capture surface water before it can flow towards the pool Drainage Case Study - Brenhaven 1
There is a retaining wall built adjacent the pool deck on the back side of the pool. The narrow deck is not wide enough for the crew to work on, so we constructed a temporary cover on top of the pool to allow more work space and to limit the amount of soil and other debris that got into the pool. Note the green water caused by the contaminated spring water that was seeping into it. Drainage Case Study -Brenhaven 2
The drainage system is complete. The French drain extends far below grade collecting water that is seeping below ground, and the surface drains consisting of catch basins connected to solid pipe will collect rainfall and direct it to the street. Note the black, domed grates of the catch basins that can be seen in this photo. Drainage Case Study - Brenhaven 3
This is another angle of the finished system. Note near the wall the strip of gravel that is an extension of the French drain gravel backfill. It is being neatly retained with metal edging. At this particular site, it was important to extend the gravel to the surface because some subsurface water was seeping out of the wall above grade and then flowing onto this property. That strip of gravel was the best way to make sure it was collected. Note the flat green grate on the left side of the photo. A surface basin was also needed in the turf to collect rainwater and divert it from the area. Drainage Case Study - Brenhaven 3