At Greensward LLC we have had an increasing number of inquires related to residential storm water management, solving drainage problems in yards, grading to prevent wet basements and controlling erosion. The weather in central Virginia has resembled that of a tropical rainforest which makes drainage issues particularly more noticeable. Clients in Warrenton, Mineral, Culpeper, Stafford, and Spotsylvania have been particularly hard hit, with storms dumping four to five inches of water on ground that has already been saturated by previous rain. The most common water problems in yards can usually be solved with several simple techniques that I will share in a series of post.
While you can do little on your own property to prevent rising flood waters in rivers, there are techniques to fix the water problems on your property while being a part of a larger solution to help mitigate large scale flooding down river. Right now, we will look at drainage solutions on residential properties. Most of the water and drainage problems around the house fall into four categories:
- Water flowing too fast (causing erosion)
- Water flowing too slow (causing swampiness, stagnant water, mosquito breeding)
- Water flowing the wrong direction (toward a house or across a sidewalk)
- Too much water flowing through the yard (from a neighbors yard above)
The commonality on all four of these water problems is FLOW. Water always moves and rain water moves down following gravity. Water will move down through soil if the soil can accept it. If the soil is too hard or already saturated, the water collects and begins to flow across the ground heading down. The more concentrated the water is and the steeper the slope, the faster it moves. The faster it moves and the more volume moving, the greater its power to erode and damage. In the case of ponding, the water can’t flow because of the soil type and grading.
In this first post, I want to look at water problems closest to home. Yep, right around your home and trying to come in type of close.
Wet and flooded basements are very costly and inconvenient! Mold, bad smells, damaged carpet and ruined drywall are just a few of the consequences of a flooded basement. In most cases, the water is finding an easy route through loose soil that was once very compacted virgin soil before the basement was dug. With our modern poured basement foundations, the contractor must dig a very large pit for the basement. Sometimes six to eight feet wider than the actual dimension of your basement walls. While the walls are usually water proofed and a drain tile is placed around the footer to drain away surplus water that collects around the footer, there is still plenty opportunity for these systems to fail resulting in wet walls or catastrophic flooding in your basement. For houses where the basement is completely in the ground, the drain tile is often routed to your sump pump which will pump the water to the surface where, if grading is right, the water will flow away down a hill. If the grading is not right, the water will percolate back down to the footer, into the tile and be recycled by the pump again and again.
This client’s yard in Fredericksburg, had a lot of settling close to their house resulting in water flowing toward their foundation. If you look at the soil in the photo as it lays against the brick which is level, you can see the soil sloping toward the house. Additionally, their sump pump emptied right next to the house causing water to recycle. Fortunately, this is an easy fix!
- Run the sump pump pipe so it daylights at least 10’ from your house, make sure the drain pipe is big enough so the water flows easily (1.5” or bigger from the sump).
- Where settling has occurred around your house, add top soil against the house and ensure at least a 5% slope away from the foundation.
- Make sure the down spouts from gutters are connected to corrugated HDPE or PVC drain pipe and carried away from the house and daylight down hill from the house.
The volume of water coming off a roof can be tremendous. Ensuring that the water that flows into gutters, then makes its way to a down spout, and then to a drain pipe running away from the house is critical to reducing the amount of water that could potentially sit around the foundation and percolate down to the foundation or basement walls. The simple splash pans or splash blocks are not enough to get the water far enough away from your foundation. They will work if your house has a steep slope away from the walls but they are not adequate for flatly graded locations.
You should also make sure your gutters are clean and properly attached. Contact Roof Works http://www.roofworksofva.com if you are in Warrenton, Culpeper, Spotsylvania or Fredericksburg, to get any gutter repairs made.
If you are near Culpeper or Fredericksburg visit A&B Kearns http://www.
In my next post, we will look at techniques for capturing large amounts of surface flowing water to prevent erosion and inundation using tools like drainage basins, trench drains, and swales.
Andrew Cutright, RLA