Water in Basement and Dry Wells-Advice Needed
We recently bought a condo that was built in 2008, and appears to be in good condition. When we bought it the seller disclosed that there were basement flooding issues in the past, but that since he installed a $10k interior drain system with 2 sump pumps its been ok. They have been working fine minus two occasions when one of the pumps jammed (debris from an electrician) during really really heavy rain.
Having read these boards, it seems to me that most people suggest keeping water out of the basement in the first place so that we don't have to rely on the sump pumps and I want to rely less on the pumps in the event that we have a really bad storm where the pumps can't keep up with the incoming water. So I had a waterproofing/foundation guy come out to assess the situation outside my house to see if there is anything we could do. This is where I want to get others' opinions, since he noticed that on our property there are what he thinks are 2 dry wells. One on the left is an open grate dry well in my driveway which collects driveway runoff and my neighbors gutter runoff and the discharge from one of my sump pumps. It looks like this dry well just seeps water out of the bottom. The other dry well is in front of the house in the garden, and is covered. I believe (although I'm not sure) that all of my downspouts are directed into this covered drywell underground. Upon opening it, this well had holes all along the sides so I'm assuming it drains out of these holes and into the surrounding soil. This well had a pipe at the top which i assume is where the gutters flow out of, and another one at the top which my contractor guessed that it may be an overflow pipe that goes to the city storm sewer if it fills too much (although this is probably useless since it would probably only fill to the top at the same time the city sewer is overflowing).
Now these 2 dry wells are basically right next to my house, one is maybe 5 feet from my foundation, the other is even less. I always assumed that they were piped into the city sewer but I guess not.
My contractor said that these wells are a bad idea since they are so close to the house, and when it rains heavily its probably just putting a ton of water into the ground around my house, and then probably going into my basement sump system. Do you think this is what causes water to enter my sump pumps? From what I've noticed the sump pumps only turn on when it is a lot of rain really quickly. For example last week we had over 1.5 inches of rain over the course of a day and the pumps never turned on, however we've had instances where it was less rain, but much more sudden where the pumps turned on (usually coinciding with street flooding).
The contractor suggested that i stop routing my downspouts to the covered drain, and he would have them run underground and then empty onto the sidewalk and then into the city drain. He would also reroute my sump pump discharges to the sidewalks as well instead of into the open dry well, and my other pump which discharges right onto the soil in front of my house. Now since my street tends to flood and the pipes for the downspout/sump discharge may get submerged in water, he also suggested installing what he called popups or release port/valves further away from the street so that the discharge pipes don't get blocked.
This is a big alteration and also fairly expensive and I just wanted to get others opinions on the matter before going ahead with this one way or another. I'm afraid that this may have some unforeseen consequences that may make the water problem worse. We have a neighbor who doesn't have drywells (although their house is much older) and their basement gets water too. Right now the water issue isn't bad, the pumps do what they are supposed to do, I just wanted to do something that would make me less worried when I'm away from home and theres a torrential downpour and be able to handle extreme circumstances.