Hot Start Files are used to define the initial heads and flows in SWMM5
The creation of the Hot Start File for your sanitary, combined or stormwater network is a three step process:
1. Save the 1st Hot Start file using an empty system as the initial conditions,
2. Use the 1st Hot Start file as the initial condition in the second run and Save the 2nd Hot Start File
3. In the 3rd Run Use the 2nd Hot Start file as the initial conditions of your network.
4. It is not necessary that the Hot Start Files be exact in the initial depths or flows but only approximate so that the network in not empty.