Inside methods are performed by installing french drains. These type of drains only keep water off your basement floor and really are not the answer to the water problem itself. The cost for a typical inside system varies with the competition,but normally a 150' basement can sell anywhere from $3,800 to $4,500.00 (quotes based on philadelphia as geological area)Doubtful your landlord will have it done, so for now consider using pallets and a de-humidifier. If you have allergies to mold and mildew, then thats another issue.