What is the minimum slope for a swale if it is located within 10 feet of a foundation to divert water?

The correct answer is based on best practices in site drainage management, particularly regarding the minimum slope required for swales to effectively divert water away from foundations. In the context of construction and site work, a slope of 3% or greater is typically recommended when dealing with drainage features like swales that are positioned near foundations.

A 3% slope ensures that water will flow away from the foundation effectively, helping to prevent issues related to water accumulation and potential moisture intrusion, which can lead to structural damage, mold growth, or other problems. This gradient promotes adequate drainage by facilitating the movement of water in a controlled manner away from sensitive areas.

In contrast, a slope of less than 3%, such as 1% or 2%, may not provide enough gradient for water to flow away efficiently, increasing the risk of pooling water and drainage problems. A slope of 5% is also acceptable and provides even greater drainage effectiveness, but the minimum required for swales near foundations is generally understood to be 3%.

This guidance aligns with many construction and civil engineering practices that prioritize the protection of structural elements from moisture-related issues. Thus, the reason that a 3% slope is the minimum in this scenario is rooted in the need for effective water management