What should the invert elevation of a 42" diameter outlet pipe be if the rim elevation of the catch basin is 70.00?

What should the invert elevation of a 42" diameter outlet pipe be if the rim elevation of the catch basin is 70.00?

• A. 65.50
• B. 64.50
• C. 63.50
• D. 63.00

Answer: (B)

To determine the appropriate invert elevation for a 42-inch diameter outlet pipe based on a catch basin rim elevation of 70.00, one must consider the hydraulic principles involved. The invert elevation is the lowest point of the inside bottom of the pipe, and it generally should be set at a height that allows for adequate drainage while preventing blockages. For a typical catch basin setup, the invert is usually set at least a minimum vertical distance below the rim of the catch basin to ensure proper flow is maintained, accounting for potential sediment deposition and minimizing the risk of overflow during heavy rain events. In practical application, a significant guideline is to provide an adequate drop from the rim elevation. A common design practice in stormwater management is to set the invert elevation a certain distance below the catch basin rim, often around 5.50 feet for a pipe of this size, allowing sufficient capacity for potential storm runoff. In this instance, with a rim elevation of 70.00, setting the invert elevation at 64.50 achieves this balance. This choice allows for effective drainage without risking overflowing the catch basin under normal operating conditions or during significant rain events while accommodating the functionality of the system. Therefore, an invert elevation of 64.50 is the most

To determine the appropriate invert elevation for a 42-inch diameter outlet pipe based on a catch basin rim elevation of 70.00, one must consider the hydraulic principles involved.

The invert elevation is the lowest point of the inside bottom of the pipe, and it generally should be set at a height that allows for adequate drainage while preventing blockages. For a typical catch basin setup, the invert is usually set at least a minimum vertical distance below the rim of the catch basin to ensure proper flow is maintained, accounting for potential sediment deposition and minimizing the risk of overflow during heavy rain events.

In practical application, a significant guideline is to provide an adequate drop from the rim elevation. A common design practice in stormwater management is to set the invert elevation a certain distance below the catch basin rim, often around 5.50 feet for a pipe of this size, allowing sufficient capacity for potential storm runoff.

In this instance, with a rim elevation of 70.00, setting the invert elevation at 64.50 achieves this balance. This choice allows for effective drainage without risking overflowing the catch basin under normal operating conditions or during significant rain events while accommodating the functionality of the system.

Therefore, an invert elevation of 64.50 is the most