**Note:** Maximum Surcharge Height Over Crown Explanation

Here is an example of how the Maximum Surcharge Height over the Node Crown is calculated. Consider a manhole with an invert of 10 feet, one incoming pipe (Pipe A), one outgoing pipe (Pipe B), both pipes with a diameter of 2 feet, but the invert of Pipe A is 10 feet and the invert of Pipe B is 11 feet. What is the Maximum Surcharge height if the HGL at the node is 17 feet?

**HGL at Node ---- 17 feet**

**Maximum Surcharge Height Over Crown is 4 feet**

**Node Crown --- 13 feet** Pipe B Crown --- 13 feet

Pipe A Crown --- 12 feet

Pipe B Invert --- 11 feet

Pipe A Invert --- 1o feet **MH Invert --- 10 feet**

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