As Civil Field Engineer, what will be your countermeasure for this ponding?

The construction of one small shelter catering air compressors was already completed, from the foundation, paving, steel structure and architectural. Remaining are only mechanical works.
Then rainy season came, almost every afternoon, rain pours.
One day, client’s engineer was doing his routine check at site.
He happens to pass by this small shelter. He noticed that there was a ponding of water inside the shelter, see attached file of ponding sketch.
Ponding is due to ingress of rain water at the shelter since it is not fully cladded.
See other related drawings for reference, Paving Plan and Architectural Plan.
Then this client’s engineer approaches Civil field engineer complaining for the water ponding at that shelter.

please note that:

1.Paving and cladding need not be modified nor repaired.

2.Air compressors are encased with enclosure and is weatherproof.