‘Storm Water’ Tag

Manhole Cover Repair

Photo Credit: Jessie Benaglio

Shown here is the repair of the top part of a manhole. This structure is a catch basin, as indicated by the type of cover. This cover is designed to be placed in line with a curb in a roadway. The fresh concrete that is supporting the cover in this photo could be called a riser or corbel. Usually, the riser is above the corbel, which is a cone shaped section which flares down into the structure. Since this is a repair, the riser and corbel are basically 2-in-1. The reason this catch basin was repaired was the settlement of the roadway over time which caused the drainage to become unlevel.

Storm Drain Outlet

Photo Credit: Karl Jansen

This is the outlet of a storm sewer system. These outlets provide a key link from the underground storm water systems found under most roads in urban areas, and the natural waterways of the watershed. Though most are hidden within brush or placed less visible places, this one is easily visible in the retaining wall near a dam.

Local Flood due to Storm Water Sewer Overload

Photo Credit: Alex Mead

Seen above is a street that has been flooded due to a storm event overwhelming the storm water sewer system. Storm water sewers are typically designed, depending on the location, for approximately a 10 year event period. This means they can handle a storm that happens on average only once every 10 years. To design for event periods much more than this would be a poor decision due to the large increase of additional resources that would be needed to accomplish these designs. As with every engineering design problem, optimal sewer design is a balance of performance and varying measures of cost.

Storm Water Storage

Photo Credit: Alex Mead

Seen here is the inside of a storm interceptor basin located near Detroit, Michigan. Most of the time this massive water storage unit sits dry, however, when a large storm hits the area, and dumps more precipitation than the sewer infrastructure can handle this tank begins to fill. The concept is that this tank can be filled and take up the extra water that is put into the system by the large rain event that the sewer system can’t handle. The water in the tank can then be filtered through the typical process once the precipitation event is over and the load on the system is lower. Tanks like this one are important because over flowing the sewer system usually results in a release of contaminated water into a natural water way.

Small Open Channel Flow

Photo Credit: Karl Jansen

Pictured here is an example of what you call open channel flow. This is a small stream of water, which eventually flows into a a pond or river. A channel is basically a geographic area where water is able to flow within some sort of physical boundary, such is the banks of a river. Open channel flow is a sub-field of free surface hydraulics.

Detention Pond

Photo Credit: Karl Jansen

Pictured here is a simple detention pond. A detention pond is a temporary place to store water, usually rain runoff from a nearby development, for a calculated period of time while it is slowly discharged. This provides an effective way to control flooding caused by developments. The water enters at the culvert end sections, and exits through the riser.

Detention Pond Riser

Photo Credit: Karl Jansen

Pictured here is a detention pond riser. The purpose of a riser in a detention pond is to manage the outflow of water from the pond. The rocks that surround the plastic tube help filter out large particulate matter such as sticks and leaves. The plastic tube is perforated with smaller holes that allow a managed amount of water to flow into the tube. Inside the tube, there is the beginning of a culvert that only allows water to exit once the elevation of the water level in the pond reaches a certain level. This culvert leads the water to it’s next destination on it’s path through the water cycle.

Concrete Culvert End Section

Photo Credit: Karl Jansen

Pictured here is a standard flared culvert end section made out of concrete. These are connected to one or both ends of a culvert. They prevent erosion by minimizing maintenance on the surrounding land by improving the hydraulics and reducing velocity of flow. Additionally, they also look better aesthetically than a bare circular ending on a pipe.

Sewer Drain Screen

Photo Credit: Alex Mead

Seen here are six screen units at an interceptor drain in Detroit, Michigan. These screens are used to clear debris from the water flowing through the drain in order to protect the pumps later on in the drain. The screens work by continuous rotating in a conveyer like motion to ensure that clean screen is always exposed to the flow. This continuous rotation ensures that the screens will never be blocked off plugging the flow of water which would cause damage to the screens.