Definitions Page

low lying area catch basin CATCH BASIN is a surface drain that looks like a box. The discharge hole is in the side of it about 3 inches from catch-basin drain the bottom of the box, allowing silt and trash to fall to the bottom, and as the water rises, it will drain down, leaving most of the silt and trash. Properly installed in low lying areas, it captures water gravitationally and provides an entrance into a drainage system.

drainage pipe core CURB CORE is a holed core removed from a cement curb in order to provide a SWPPP approved exit for the drainage water. The end of the drainage run requires an outlet; this is one option for the termination of a drainage run. (Compare this method to Daylighting, Grate and Pop-up Emitter).

daylighting diagram DAYLIGHTING is a method used to provide an exit for the end of a drainage run. Sometimes this method is used to save money by omitting a proper exit path via a cored curb or a pop-up emitter. (Compare this method to Curb Core, Grate and Pop-up Emitter).

FRENCH DRAIN is a complex system including perforated drainage pipe, surrounding drainage rock, a slope and proper exit point. A French drain is designed to access and drain french drain build-out both sub surface water and surface water. The extraction of subsurface water through the drain creates a void which allows the surface water to gravitationally flow into the French drain.

Caution: even though many call all drainage corrections a French drain, really subsurface moisture problems are the only place for a French drain.

drain grate GRATE is a fitting that is placed over catch basins or directly on pipe. It can be used as a termination cover for the end of a drainage run fitted directly onto the pipe. (Compare this method to Curb Core, Daylighting and Pop-up Emitter).

PERMEABILITY is a characteristic of rock or soil that allows water to pass through it, varying in different degrees according to the amount of separation between the soil or rock particles.

PIPE -- SOLID AND CORRUGATED

CORRUGATED SOLID PIPE is used for water removal when infiltration is not needed. Commonly used in gutter downspout drainage runs and as extensions for French drainage runs to reach a designated exit. Flexibility is a benefit for ease of design under stone edging, around trees or other underground obstacles.

CORRUGATED SLOTTED or PERFORATED PIPE is used in subsurface drainage correction that has holes in about 80% of its sides. The perforations allow water to seep into the pipe. Flexibility is a benefit for ease of design under stone edging, around trees or other underground obstacles.

CORRUGATED PERFORATED FABRIC FILTERED PIPE is used in French Drain solutions where permeation of subsurface water is desired and prevention of soil infiltration is required to keep the pipe free from debris. Flexibility is a benefit for ease of design under stone edging, around trees or other underground obstacles.

slotted & solid white pipe SLOTTED WHITE PIPE can be used for subsurface and surface water removal and can be used in French Drains. Pipe comes in 10’ or 20’ sections.

SOLID WHITE PIPE can be used for straight line drainage applications for channeled water removal such as end of drainage runs for under hard surfaces such as concrete or sidewalks and through cored cement curbs. Pipe comes in 10’ or 20’ sections.

POP UP EMITTER is a device at the end of a drain pipe that hydraulically pops up to allow water an exit point. The device is normally closed and prevents small animals, small children and debris from entering the end of the drainage run. When the system is active, rainfall running through the pipe creates water pressure to open the lid for water release. Frequently used in a turf area, slope should be sufficient at exit to prevent puddling. Benefits include enabling a shorter drainage run (saving linear ft costs) and some reuse of the residual water in a turf area (provided it is healthy enough, appropriately sloped, etc.).

SLOPE – After materials, slope is the single most critical element to the success of a drainage solution. Proper slope should register at least ¼” slope per foot of drainage pipe. Drainage pipes are a gravity based design to carry water and therefore require minimum but consistent slope throughout the run.