What is a critical design feature of an effective infiltration basin?

Proper sizing is essential for the effectiveness of an infiltration basin because it directly impacts the basin's ability to manage and treat stormwater runoff. When an infiltration basin is appropriately sized, it can capture peak runoff volumes during storms, allowing for adequate infiltration into the soil. This helps to reduce flooding and promotes groundwater recharge.

If the basin is too small, it may overflow during significant storm events, leading to potential flooding and reduced performance in filtering contaminants from the water. Conversely, if the basin is oversized, it may lead to unnecessary costs and maintenance efforts without a corresponding benefit in stormwater management.

In contrast, a concrete flooring would inhibit absorption, preventing the basin from functioning as intended; an unsealed bottom may not provide adequate drainage control, leading to overly rapid drainage that can affect water quality and surrounding areas; and a steep slope could increase runoff velocity, potentially overwhelming the basin's capacity. Thus, proper sizing is a critical design feature for ensuring the effective operation of an infiltration basin.