As a landscape company that deals with drainage issues, one frequent source of calls we get in Victoria BC around winter are flooded driveways and garages. Rather than being reactive, this guide will hopefully allow one to think more proactively.
Flooding in driveways and garages are generally caused by a couple of things. One is slope, in which the street and sidewalk are higher than the garage thus the driveway slopes down towards the house. This of course means any water collected by the driveway and sidewalk runs downhill straight into your garage. Another is excessive drainage from downspouts that don’t have a proper exit. Often we also see existing drains that are either clogged, too small, or due to settling, no longer the lowest spot.
For an existing drainage system, one can try to run a snake through it to try to unclog it. This often takes specialized equipment to see what’s going on. There are landscape and drainage companies that have cameras on the end of a long snake to see what’s going on. This has the benefit of being a relatively cheap option but is not guaranteed to solve your problems as it would not fix a drain that is too small nor a drain that is too highly elevated.
A great solution is to essentially install a new drain system in the shape of a trench system. This allows a far superior surface for water collection, is aesthetically pleasing, and is ensured to be the lowest point for water collection.
To install this, we typically find the lowest area, usually right in front of the garage door, and cut a trench into the concrete. A grated drain box is then installed in that trench with the dimensions such that a vehicle’s tires never puts pressure on the grate itself. An exit is also installed to evacuate the water collected, often into an existing down spout drainage system. If that is not available, other traditional systems can be used depending on the lay of the property such as a sump pump, drainage basin, etc. The entire system is then reburied and reset in concrete to ensure it blends in seamlessly with the existing terrain.
That’s essentially it. The difficulties are generally working with concrete which requires specialized tools such as a concrete saw and finding a desirable outlet to evacuate the water. Installing such a system should provide a solution to any flooded driveways or garages for years to come as such a large drain is far less likely to clog than a single small round drain.