Although water in your swale can be concerning and unsightly, don’t panic, it is actually a natural state for a functioning swale. The swale is designed to catch the runoff from the roadway and the adjacent properties and send it to an outfall, such as a ditch or basin. The other functions of a swale are to capture pollutants before they enter a water way and the eco system as well as allow some of the water to percolate into the ground and help to recharge our aquifer (where we get our water from). An average swale is one foot deep. A small amount of water in the bottom of the swale will not have any real effect on how the swale functions during a major rain event, such as a hurricane.
There are many reasons why a swale can hold, there could be a blockage downstream that is backing water up.
There is something below ground, such as clay or hard pan, that will not let the water percolate.
One of the most common reasons is a buildup of dirt in front of or in the driveway culvert. Maintenance of the driveway is actually the homeowners responsibility. By simply removing the buildup periodically, the swale will continue to flow freely and help prevent water from pooling in the swale. If your pipe is blocked and you cannot clean it yourself you can contact the City to have the culvert cleaned out.
During periods of heavy and/or consistent rains the water table can raise up high enough that it is above the bottom of the swale. This is a temporary condition. When the rains stop and the water table goes back to normal your swale should return to the same condition it was before the rain started. A simple way to tell if this is what is going on in your swale is to follow the swale down to where it outfalls (ditch or basin). If there is water in all of the swales and water is running into the outfall, even if it is not raining at that moment, then this is most likely just high ground water.