I need to produce a flowchart for the following Arduino sim: Please help

The Scenario

FIGURE $1$ shows part of a control system used to maintain the water level in a

sump between the levels high and low. Two transducers $($HIGH and LOW$)$ are

used to monitor the level. The water is pumped out by two pumps, P$1$ and P$2.$

The water level in the sump is to be controlled as follows:

If the level reaches high one pump will start to pump out.

If the level does not reach low within about $30$ seconds, the second pump

will come into action. If the level does reach low before $30$ second

pumping should stop.

If the level does not reach low within about $30$ seconds of the second

pump starting, an alarm is given. The alarm is sounded until the level

reaches low. If the level does reach low before $30$ seconds the pumping

should stop.

The pumps will stop when low is detected.

To give even loading of the pumps they are to be used alternately, e$.$g$.$ if

on one pump cycle P$1$ starts first and P$2$ is the 'back up$\text{'}$ then on the next

cycle $P2$ will start first and $P1$ is the 'back up$\text{'}.$