What is the minimum allowed slope of the bottom of a trench drain?

The minimum allowed slope of the bottom of a trench drain is designed to ensure proper drainage while preventing water pooling. A slope of 1/8 inch per foot is the correct standard because it provides a gentle enough incline to facilitate the flow of water towards the drain without causing undue strain on the material or structure of the trench itself. This slight slope is critical in keeping the water moving effectively away from the area, reducing the risk of stagnation and potential flooding.

Choosing a steeper slope, such as 1/4 inch per foot or more, could lead to increased wear or damage to the trench drain over time and may not provide enough surface area for the water to adequately distribute before reaching the drain. Therefore, maintaining the minimum slope of 1/8 inch per foot strikes a balance between efficient drainage and the longevity of the trench drain system.