Census information for Amherst (Buffalo County, State of Nebraska). Contains: population counts from the 2010 Census and estimated counts up to 2016, Population Rings and much more.
Please try again later. This is the end point of a 70ft french drain constructed with 6in Multi-Flow product encased in coarse sand. The water is flowing into a 4inch PVC pipe via a tee connection. There is already some flow in the 4inch PVC from the upstream downspout lines that run under the french drain line. 1  Film & Animation.
After locating the best area for a French drain. Trench lines should be plotted out before you begin digging your French drains. Obviously the French Drain does not have to go in a straight line but it does have to slope at least at a 1% grade. A 1% Grade would have a drop of 1 foot for every 100 feet in length. Check your Slope as you as you go. For instance, if the trench for the French Drain is to be 100â long and the grade 1%, then by the time your trench is 50â long, the drop should be 6â. 3. Using a water level to check your progress is easy.