Frequently Asked Questions
Q: Why do I need a Drainage and Grading Plan? I’m just building a garage/pool/sunroom/small addition/new house and I’m not changing anything?
A: We get asked this question more than any other when it comes to single family residences. The answer is twofold. The main reason is to protect your own home. A well designed site will effectively convey stormwater away from the house. Storm water pooling at the foundation is one of the primary causes of basement seepage. The second reason is to protect your neighbors. A properly designed site drainage plan will convey the water away from the property line to the front and rear of the properties, where it can drain to a public right of way or other storm water collection device. Municipalities hate getting involved in neighbor disputes, so they require a grading plan to be prepared by a licensed Professional Engineer to come up with an individual solution for each property.
Q: I have the lowest lot in the block, why do I have to accept by neighbor’s storm water runoff? Why can’t I just block it and let him deal with his own water?
A: Illinois drainage law states” Landowners, including highway authorities, have a right to drain water away as it would in a state of nature. Lower landowners, including highway authorities, have a responsibility to accept water flowing naturally onto or through their lands and have no right to interfere with such natural drainage.”
So this means you cannot block or dam the water at the property line to keep your neighbor’s water from coming onto your land. This is commonly achieved by grading a shallow drainage swale on the side yards to convey water to the front and rear yards and by having the downspouts be directed to the front and rear yards.
Q: Every time it rains I get water in my basement. What should I do? Everyone I talk to tells me something different.
A: The best solution is different for every house. Are you getting seepage or sewer backup? Is water coming over the top of foundation or from stairwells? Is the basement damp? Bono Consulting Civil Engineers have developed a thorough inspection checklist to review site conditions both inside and outside of the house to diagnose the root of the problem from an engineering fundamentals point of view. Once we know the cause of the problem, we recommend a solution. The solution is different for each house, and we provide a non-biased opinion that is not tied into any specific technology.
The most important issue is usually to get surface water runoff, downspout discharge and sump pump discharge away from the building and conveyed to the right of way. We typically recommend back-up sump pumps, and overhead sewers. Internal foundation drains do a lot to dry out basements. Contact us and we can make an appointment to review your individual situations and steer you towards the specific fix your home requires.
Q: What other permits do I need?
A: If you are constructing a residential building that has 25 or more units, or has any mixed use component; you will need a permit from MWRD for the sanitary sewer connection. This applies to the Cook County MWRD service area, not including Chicago. If you are constructing storm sewers in a combined sewer area you will also need an MWRD permit. If you are constructing a new water main extension, you will need a permit from the IEPA. If you are constructing a new sanitary main extension, you will need a permit from the local sanitary authority as well as the IEPA. If you are disturbing more than one-acre of land you will need an IEPA Notice of Intent for Construction permit and a Stormwater Pollution Prevention Plan (SWPPP).
Q: What is Compensatory Storage?
A: The floodplain can be considered to be large bowl of water. If the bowl is full and you place something into it (a building, an earth berm, a garage, etc.), the water level rises. This would cause the flood to go even higher. So, FEMA says if you want to build something in the bowl (floodplain), you have to compensate for it by making more room in the bowl. This is usually done by excavating another part of the site down to offset the proposed fill volume. This cut volume is the compensatory storage.