Drain for Storms

There are many ways that architects and civil engineers design project sites to control water drainage during storms. We utilize all of the below methods and more to manage the flow of water during a storm.

A project and its final realization in the constructed building and site changes the site’s most recent configuration. It could be that the site has been untouched for decades or has had many things done over the course of the years. Regardless, the new construction alters the way that water has been handled at the site. As an example, a relatively untouched site with ground cover would have about 10% drainage. If you add impervious surfaces, that amount increases to 55%. Site drainage must be handled appropriately.

Because in Mississippi, regardless of a project’s being located in Madison, Jackson, Biloxi / the Gulf Coast or Oxford, Mississippi State, Meridian or other Mississippi Cities where we have had projects, in Mississippi, we handle an above average (for the country) amount of rain, and so we must deal with the site water and its effluents using appropriate means.

We build the projects based on the approved designs and utilize all of the features specified in order to make the project work.

The main priority, though, is ensuring that water is handled in a way that doesn’t promote erosion. The design must stop water from running away and bringing with it contaminants, pollutants, and other things that would not be helpful for the short and long term health of the site.

The typical storm drainage components include:

• Catch Basin – A catch-basin is a storm drain. In many situations, it is the primary way of draining landscaped areas. It is responsible for channeling water away from components of construction that may be harmed by water accumulation and sent to means of removing the water like trenches and pipes to another location. Catch basins collect runoff water from rain or snow having melted and directs the water to sumps, treatment facilities, reservoirs or other means of allowing the water to be absorbed or percolated back into the soil. They contain inlet and outlet pipes which serve to channel the water away.
• Catch basins typically have a metal grate over them, allowing the screening of major debris away while allowing water to pass through. At times, these grates can become dirty and clogged with trash, leaves and such things. The debris need to be removed in order for the catch basin to function properly.
• The Catch Basin is typically located at the lowest part of the property, although intermediate ones may be located at strategic places in order for water to accumulate and then be channeled to other places. The Catch basins may have a depth lower than that necessary to channel the runoff, which serves as a means of catching additional debris before it is channeled to another location.
• Limitations of Catch Basins – Catch basins for landscaped areas not frequently encountering heavy loading conditions from truck and cars are made of plastic. Others which would be exposed to heavier loads on streets are made of poured in place or prefabricated concrete units. Some are made from CMUs (Concrete Masonry Units).There are a variety of thicknesses of wall sizes used for catch basins. These thicknesses are used to bear the loading conditions anticipated at the project site. As an example, sand, gravel silt or soil catch basins can take light traffic at 60 psi. 4” thick walls allow for light vehicular traffic up to 175 psi. 6” thick walls can carry semi-trucks and 8” carry heavy duty lifting equipment such as fork lifts. Each respectively carries 325 to 575 psi. Again, the Civil engineer for your project would design the walls according to anticipated loading conditions.While at times a necessary component of storm water conveyance systems, they do not filter everything and can easily become overwhelmed if an extreme rainwater event occurs. So, they are not especially good for the removal of pollutants, silt, colloidal mixtures and the like.
• As you can probably tell, there are many nuisance insects, especially mosquitoes, in Madison Mississippi and the surrounding areas. Catch basins, if not cleaned on a frequent basis, can serve as a breeding ground for these pests you love to hate.
• We install catch basins into projects when the architect or civil engineer has determined that they are necessary in order to accommodate the anticipated rainwater events likely in Mississippi.
• Trench Drains –  A trench Drain is a Ground Gutter. Where Catch Basins serve as a focal point for all of the water drainage to come to, the Trench Drain serves as a channel and collector of the runoff water in order to then send it to the conveyance system. The trench drain is needed specifically where you need drainage to occur, but don’t want to disrupt the planar surface like catch basins would disrupt it. As an example, a catch basin requires that the areas immediately adjacent to it are sloping in its direction. If the CB is a rectangle or square, then all adjacent surfaces would slope into it. At times the sloping can disrupt the areas around it and impede the maximum slopes needed for accessibility purposes.
• As well, Trench Drains can provide a more aesthetically pleasing alternative to a Catch Basin. Trench Drains can have metal grating work covering them that is decorative and can itself blend into its surroundings better.
• Trench Drains are typically four inches to two feet. The amount of water to be drained serves as the width determiner, as well as the depth needed for the trench drain.
• The Load Class, similar to Catch Basins, varies based on the need to handle weight being put on the trench drain. A load class ‘A’ differs from ratings all the way to ‘E’ or ‘F’ in that ‘A’ is rated for foot traffic primarily and E / F can carry up to 10,000 pounds.
• Rip-rap – Stones or concrete rubble placed in order to minimize the effects of running water. The effects of running water alongside of structures can remove the soil, earth or other structures around it- called bridge scour. Rip-rap is used to minimize the effects of bridge scour. Rocks typically used range in sizes from 4 inches to two feet, where the larger sizes are placed alongside water that will have high speed and lower sizes for diminished speed. Rocks may be loose or grouted together. It limits erosion associated with wave action.
• Drainage ditches – commonly seen alongside roads, drainage ditches carry off excess water. They are essentially long trenches which divert the course of the water toward other site elements such as ponds. Ditches should be twice as wide as they are deep and may use rip-rap in order to control flowing water.

In the video below, please find examples of managing storm-water drainage at a construction site:

Means and Methods

• Methods change based on the type of project. A highway or street drain will need different receptacles than roof drains. We handle all of it.
• Drainage ditches with filter fabric and rip rap are common fixtures at sites we handle as well as retention ponds, dredging services, catch basins and drain inlets. We handle all of it through combining our knowledge and understanding with improved drainage for residential and commercial properties.
• Installation of storm drainage piping, draining inlets and outfall structures are all ways that we have controlled erosion before. We are experts at our work.

Call us today at (601)326-2894 or fill out the form for a free quote!