Why are there storm water ordinances and why are detention/retention ponds always so big?
As communities grow, more impervious surfaces (roads, parking lots, buildings, sidewalks) are constructed. Impervious surfaces generate larger amounts of storm water runoff. As this runoff accumulates downstream, there is a greater tendency for the downstream areas to flood. To prevent downstream flooding, communities now usually require that you release water at a controlled rate equal to or less than what was being released prior to development. The remainder of the water has to be stored on site. Typically, the basins are sized to hold a storm event that is predicted to only occur every 25 years. This is why the detention/ retention ponds are always so large. In some cases, the basins have to hold 100-year storms! What is an “engineered septic system” and when are they required? The local health department sometimes require engineered septic systems when soil or groundwater conditions are not ideal. They can also be required when the field is located uphill from the home. Engineered
