The only question relating to it in the disclosure form my realtor sent me is: "I am aware of flooding or recurring leakage problem in my crawl space or basement" and "I am aware of leaks or material defects in the roof". 

Should probably add a leakage line item into underwriting based on % of furnishing cost just like the standard for CAPEX and maintenance. 

The better investment would be to have your home tested for air leakage and insulation efficiency.

Will lender consider high risk in lending to house purchased next to (ie, in-home grow Marijuana, or house with sewer line or roof leakage problem? 

The GC charged additional fees to “correct” the work, but merely covered up the old pan, leading to water leakage into the basement and mold growth.

If his high usage is winter which for most people in colder areas then check for air leakage and need for insulation.  2.  

In September 2024, I purchased an investment property and the tenants immediately began reporting water leakage through the basement walls (seepage).

We had the person fixing the plugged line address both units and verify that there was no more leakage into the lower unit.  

Basically it must be sealed to keep any ground water out and any water that does get in (either through leakage or flooding above) must be pumped out.

I am working with my PM comany to investigate water leakages or tenant misuse but beyond that any suggestions on how to handle this situation?