Stormwater management regulations were enforced to protect fresh water systems from pollution due to penetration of stormwater runoff.
Runoff refers to rainwater that flows through urban areas with impervious surfaces, taking along with it gasoline, debris, excreta, and other harmful chemicals.
The steadily increasing number of stormwater basins found right underneath all cemented structures which store and infiltrate runoff can be attributed to stormwater management regulations.
Stormwater systems should be applied whenever new concrete structures are to be established.
While stormwater systems can be utilized for infrastructure in various ways, a primary consideration should be taken into account.
This consideration is whether to use above-ground systems or under-ground systems.
Above ground systems make use of wet or dry ponds and grassy swales as their permeable surface.
These structures are placed near concrete buildings or parking areas at a more slightly sloped angle to receive runoff from the concrete surfaces better.
The runoff from the concrete buildings and parking lots should be directed into the water collection basin (ponds and grassy swales).
From here, it would either collect and soak into the soil (known as infiltration) or drain through a weir system to another receiving body of water which is at a slightly lower angle than the inflow (detention).
Under-ground systems may include utilizing various types of equipment and mechanisms.
The most standard form of this stormwater system is directing stormwater runoff into drains where the water would collect and infiltrate into the soil below the collecting area.
More innovative means of stormwater containment have been developed to more effectively manage and store runoff.
Under-ground systems make use of concrete vaults, pipe chambers, and plastic structures.
Such systems are used in parking lots, highways, sports arenas, and other grassy areas.
Aside from selecting which stormwater system to utilize, another consideration would be whether to apply detention or infiltration systems.
Detention-type systems first store stormwater in a collecting basin before discharging it by means of a controlled outflow.
Infiltration-type systems allow stormwater to freely permeate into the porous surface of a collecting basin and into the ground below.
In selecting between detention-type and infiltration-type stormwater systems, other factors must be first considered.
A location's soil quality should first be assessed before deciding to go with either detention or infiltration.
Sandy soils enable unhindered infiltration of stormwater into the ground, while clay soil would provide an impervious base and let as little water pass as possible.
Another factor to consider is where the system will be located.
If it is on an area near a body of water, detention systems are often preferred over infiltration systems.