What is the function of a gravel or stone diaphragm in stormwater management?

A gravel or stone diaphragm plays a crucial role in stormwater management by spreading water flow evenly across a given area. When stormwater runoff occurs, it often needs to be managed to prevent localized flooding and erosion. The diaphragm, made of gravel or stone, helps to dissipate the energy of the flowing water and encourages it to disperse gently over a wider area rather than concentrating in one spot.

This even distribution helps minimize the velocity of the water, reducing the risk of soil erosion and enabling better infiltration of water into the ground. By controlling how stormwater moves, a gravel or stone diaphragm can significantly enhance the effectiveness of stormwater mitigation strategies, ensuring that rainfall is managed more effectively and sustainably.

While it is true that gravel can filter out some pollutants, its primary function in this context is to manage and distribute water flow. Similarly, storing stormwater and reducing erosion are important aspects of stormwater management but are not the direct functions of a gravel or stone diaphragm. This specific design feature addresses the immediate need to manage flow rather than the broader functions of filtration or storage.