Search results
Results from the WOW.Com Content Network
Impervious surface percentage in various cities. The percentage imperviousness, commonly referred to as PIMP in calculations, is an important factor when considering drainage of water. It is calculated by measuring the percentage of a catchment area which is made up of impervious surfaces such as roads, roofs and other paved surfaces.
These consist chiefly of clay soils with a high swelling potential, soils with a permanent high water table, soils with a claypan or clay layer at or near the surface, and shallow soils over nearly impervious materials. These soils have a very slow rate of water transmission (final infiltration rate less than 0.05 in (1.3 mm) per hour).
The walls of a planter extend 3 to 12 inches above the soil bed to allow for ponding within the unit. The thickness of the soil growing medium ranges from 6 to 24 inches while gravel beds are 6 to 18 inches in depth. The planter's capture ratio is the ratio of its area to the impervious area whose runoff it captures.
A stormwater fee is a charge imposed on real estate owners for pollution in stormwater drainage from impervious surface runoff.. This system imposes a tax that is proportional to the total impervious area on a particular property, including concrete or asphalt driveways and roofs, that do not allow rain to infiltrate.
The sign designation for a state-specific sign includes a "(CA)" after the sign number. The CA MUTCD also defines some state-specific series: [8] Series G: California Guide; Series SG: California Special Guide; Series S: California Special Information; Series SC: California Special Temporary Traffic Control; Series SR: California Special Regulation
In addition to reducing surface runoff, permeable paving systems can trap suspended solids, thereby filtering pollutants from stormwater. [ 2 ] Permeable pavement is commonly used on roads, paths and parking lots subject to light vehicular traffic, such as cycle-paths , service or emergency access lanes, road and airport shoulders, and ...
The Unified Soil Classification System (USCS) is a soil classification system used in engineering and geology to describe the texture and grain size of a soil.The classification system can be applied to most unconsolidated materials, and is represented by a two-letter symbol.
A drainage equation is an equation describing the relation between depth and spacing of parallel subsurface drains, depth of the watertable, depth and hydraulic conductivity of the soils.