How many percentage should I refund ?

[Villa-Serenity0]

Dear senior hosts,

I had 7 guests , staying for 4 days.  The last night mid night, there was water dripping on second level due to drainage blocked by tree leaves and heavy rain.

Total rooms : 5

Affected rooms:   3

Dripping issue:  just a bit ,  it resolved just after cleaned the drainage 

As 5 rooms are all family rooms and each rooms can sleep 3-4. So they may even not use the  second level or not all the 3 affected rooms. But anyway they just showed me the pics that the three rooms got the issue. 

May I have your advice that how many percentage that  I should refund to the guests ?

Thanks so much for your kind help ! 

[Villa-Serenity0]

Hi all senior hosts, 

I just wrote a letter to the guest 

I will refund based on the following 

Compensation = Payment for the forth(affected) day 

X

0.5 (ground level not affected, only second level affected =half of the affected area)

X

0.5 (50% refund for affected area for the day)

Is it fair for the guest and fair for me as a host?

Honestly,  the water dripping is really  neglectable. 

[Villa-Serenity0]