There is no question--these are a nightmare for everyone. In addition to damaging personal property, creating great conditions for the growth of mold and making a huge mess....the most important thing to remember about water in the basement is that it probably came from roof and ground water that you failed to adequately control. In this region it is extremely unusual to be unable to control basement moisture by taking some common sense measures that may involve time and labor but not necessarily a lot of money.
Grading at the foundation is critical! Since the construction trench around the foundation was backfilled with disturbed soil it is usually less dense than the surrounding soil and frequently has settled to create a shallow recess that can hold surface water against the foundation. This is definitely BAD! Roof water runoff and ground water can also soak down into this soil and build up against the masonry wall causing a wet basement or putting hydrostatic pressure on the foundation wall. This is also BAD! Eventually the foundation walls may bow and break under the load imposed by the water. Consider regrading this area by banking the soil so it slopes away from the house, dropping 1" per foot for 4 or 5 feet out from the wall. Covering this soil with black plastic sheeting (with holes torn at strategic places to allow root water for plants) and then using a coarse mulch as a ground cover can be quite effective as a watershed. If there are planter curbs, timbers or other water-retaining garden edgings, the best option is to remove them. If you must keep them, try to regrade them flush with the top so water will waterfall outside rather than being trapped inside. Drainage holes in the edging can also help water escape. NOTE: Evaluate your situation carefully before taking action! Sometimes conventional regrading can lead to the burial of wooden elements such as trim or wooden window or door components, cover the base of the air conditioner compressor or facilitate insect infestation. This can lead to simply exchanging one problem for another. Watch out for these pitfalls!!
If the slope of your yard or your neighbors yard is toward your house be especially cautious. Sometimes good foundation grading can serve as an earthen "berm" to channel water around the house. More extreme conditions may call for a regrading of the yard or the use of swales and other external ditches or channels to keep water away. Make sure your gutters and downspouts are clean and in good working order and make sure that they discharge water at least 5' away from the foundation of the house.
By following these simple guidelines you should dramatically reduce, if not completely eliminate, water problems in the basement. It is our experience that a landscaper can handle about all of the work necessary to regrade around the foundation. In general, there is no need to get waterproofing companies involved and in fact, we tend to recommend against them. Our concern is that waterproofing products may keep the water outside the walls but they don't decrease the hydrostatic load on the wall and may, in fact, increase it thereby increasing the probability of foundation failure. Whatever you choose to do must involve getting the water load away from the walls. If you need further assistance on this give us a call--anything we can do by phone from a chair is free!!