Erosion Control on a Residential Lot
Your lot is about to be stripped. Whether it is a half acre in Navarre or a wooded acre outside Pace, the day the brush and roots come off is the day the sand starts looking for a way out, and it will find one in the first hard rain. Erosion control on a house lot is not complicated, but it is easy to do badly. Here is what it actually takes and why each piece is there.
Why sand leaves a bare lot
Under the trees, the ground was held together by roots, leaf litter, and the mat of stuff that had been growing and dying on it for decades. Strip that off and rain hits bare sand at full speed. Sugar sand has nothing holding one grain to the next, so the water picks it up and carries it wherever the lot slopes, which is usually the road ditch, the neighbor's yard, or the nearest bayou. On the clay inland, the surface seals and crusts, so instead of soaking in, the rain runs off in a sheet and takes the loose top with it.
Either way, the dirt leaving is dirt you paid for. On a pad that was brought up with hauled fill, a season of washing can take the edge off the pad and leave a slab corner sitting on less than it was built on. And once it crosses the property line, it stops being your fill and starts being your problem.
Silt fence goes on the low side, and where else
The point of silt fence is to slow water down enough that it drops the sand it is carrying before it leaves the lot. So the fence goes where the water leaves, which means the low side, and any other spot where runoff can get off the property. Walk the lot after a rain before anything is cleared and you will see exactly where that is, because the water has already drawn you a map.
It goes in properly or it does not work. The bottom of the fabric gets trenched into the ground and backfilled so water cannot run under it. The stakes go on the downhill side so the fabric leans into the flow instead of folding over. The ends turn uphill so water does not just run around them. Across a swale, where the flow concentrates, the fence needs help from a straw wattle or a rock check, because a fence alone will blow out there. And it does not need to wrap the whole lot. Fence on the uphill side is fence doing nothing. NOBL keeps a state certified erosion control inspector on staff so it goes in that way on every job.
The entrance rock
The gap in the fence is the entrance, and the entrance is where the mud goes out. A pad of rock where the driveway will be gives the trucks a firm place to come in and out, knocks the mud off their tires before they hit the pavement, and keeps the lot from getting cut into ruts that turn into new channels for water. It is part of the site prep we put in with the silt fence, before the clearing starts, not afterward. Mud on the street is the thing the neighbors notice first.
Covering bare ground
Fence catches sand that is already moving. The better move is to keep it from moving at all, and the way to do that is to not leave the ground bare. Any part of the lot that is not going to be worked for a while gets seeded and strawed, or sodded on a slope where seed will not hold. Stockpiles of topsoil or fill get seeded or covered rather than left to wash. The finished pad gets crowned so water runs off it instead of sitting, and the slopes off the edges get stabilized before the builder's crews arrive and start walking them down.
This is the step that gets skipped, because a bare lot does not look like a problem on a dry afternoon. It looks like a problem in the road the morning after a storm.
Maintaining it through the job
A silt fence that went in right in March is not the same fence in August. Sediment builds up against it until it is full and starts to overtop. Fabric sags between stakes. A delivery truck backs over a section and flattens it. A sub pulls it aside to get a trailer in and does not put it back. The entrance rock disappears under a layer of mud and stops doing anything. That is what a construction site does to erosion control, and the difference between a lot that holds its sand and one that does not is whether anybody walks it and fixes it.
On our jobs, the fence and the entrance get looked at as part of the work, not as something thrown up the day before somebody comes to look. After every storm, somebody walks the line, cleans out the sediment, restakes what sagged, and closes the gaps. When we hand the lot over, the fence is standing and the bare ground is covered, and we tell the builder what needs watching for the rest of the build, because the build goes on long after we leave and the fence has to last the whole time.
Get it set up right at the start and keep it up, and erosion control is a small part of a lot. Skip it and it turns into a cleanup, a regrade, and a conversation with the neighbor, all of which cost more than the fence.
NOBL Sitework is a licensed general contractor (CGC1537340) handling site preparation and erosion control across Santa Rosa, Okaloosa, Walton, Escambia, and Bay counties. If you are about to clear a lot and want it set up so the sand stays put, call us at 850-238-3307 and we will walk it with you and show you where the water is going to go.
