What action should be taken immediately after shutting down a hydrant?

After shutting down a hydrant, it is crucial to check for leaks. This action is essential because it ensures that there are no residual issues with the hydrant or the connections that could lead to water wastage or pressure loss in the system. Checking for leaks not only confirms the proper operation of the hydrant but also helps identify any potential problems that could affect future use.

If leaks are detected, they can be addressed promptly to maintain the integrity of the water supply system and ensure operational readiness for future firefighting needs. This proactive approach helps prevent more significant issues down the line, such as water loss or damage to the surrounding infrastructure.

The other options, while potentially relevant in different contexts, do not take priority immediately after shutting down the hydrant. Notifying the control center may be necessary depending on the protocol of the fire department, but ensuring the hydrant is secure and leak-free should be the first step. Reopening the valve doesn't apply in this scenario, as the valve has just been shut down. Inspecting the nozzle is also important, but it comes after confirming that the hydrant itself is functioning as it should and is not leaking.