What type of water main is supplied from only one direction and usually results in poor flow?

The type of water main that is supplied from only one direction and tends to result in poor flow is indeed a dead end main. In a dead end main, water flows to the end of the line without any further routes to return; as a result, there can be stagnation, which may lead to sediment buildup and reduced water quality. The lack of a continuous flow can create issues with pressure and can hinder effective fire protection capabilities, as the volume of available water may not meet the demand.

In contrast, a looped system incorporates multiple supply lines that connect back to the source, promoting better circulation and pressure maintenance. A grid main also allows for multiple pathways for water to flow, enhancing system resilience and performance. A circuit main is designed to provide two or more directions of flow, further improving reliability and reducing stagnation. These alternative designs are used to ensure an efficient water distribution system with consistent pressure and flow rates, critical for firefighting and other essential services.