Do I have recourse on a home I purchased less than 90 days ago?

Its difficult to say without knowing more.  The essence of the issue is 1) did the condition leading to the flooding exist prior to your purchase and 2) did the sellers know about it a fail to disclose it to you?  Its often difficult to prove the first of these two.  Even if you can prove both 1 and 2, sellers often will not pay to fix the problem post-sale without you filing suit and incurring the expenses of a lawsuit.  You won't recover your attorneys fees.