BASIC TERMINOLOGY


 

Backfilling .................. Placement of excavated soil in the trench after blinding has been completed.

Bedding ....................... The earth foundation of the trench together with the select material around and over the drain, including envelope and filter material where used.

Berm .............................. Strip or area of land, usually level, between the spoil bank and the edge of a channel or ditch.

Blinding ........................ Placement of select soil around a drain to prevent damage or misalignment when the trench is backfilled and to allow water to flow freely to the drain.

Coefficient of roughness           Factor expressing the frictional resistance to flow of a channel surface or a drain interior.

Connections ............... Fittings used to join two drain lines.

Continuous pipe ...... Extended length of pipe without perforations or unsealed joints.

Deflection .................. Decrease in vertical diameter of tubing, often influenced by loading.

Ditch ............................. Constructed open channel for conducting water. See Drain.

Diversion .................... Channel constructed across the slope for the purpose of intercepting surface runoff.

Drain ............................. Conduit below the ground surface for removal of surplus ground or surface water. See Ditch.

Drainage area ........ Area from which drainage water is collected and delivered to an outlet. Sometimes referred to as the watershed area for a particular drain.

Drainage coefficient       The depth of water, in inches, to be removed from an area within 24 hours.

Drainage system .. Collection of surface ditches or subsurface drains, together with structures and pumps used to collect and dispose of excess surface or subsurface water.

Field ditch ................ A graded ditch generally crossable with field equipment for collecting excess water from a field.

Grade or gradeline         Degree of slope of a channel or natural ground.

Inspection well ...... Opening to surface in drain line to permit observation of flow conditions.

Interceptor line or drain          Surface ditch or subsurface drain, or a combination of both, designed and installed to intercept flowing water. Also, a line used to intercept several lines to keep the number of crossings at highways and similar locations to a minimum (also called collector lines).

Junction ...................... Point of intersection of two or more surface ditches or subsurface drains.

Lateral ditch ........... Principal channel or ditch that conducts drainage water from the field ditches to an outlet channel.

Lateral drain ........... Secondary drain that collects excess water from a field.

Main drain ................ Principal drain that conducts drainage water from the lateral drains and submains to an outlet.

Outlet channel ........ Channel constructed primarily to carry water from manmade structures such as drain lines, surface ditches, diversions, and terraces.

Pipe ................................ A continuous length of non perforated conduit typically used to protect an outlet or to provide additional structural strength.

Pipe drop inlet ...... Type of surface water inlet, fabricated from pipe materials, which lowers surface water to a ditch bottom.

Pumping plant .......... One or more pumps, power units, and appurtenances for lifting drainage water from a collecting basin to a gravity outlet.

Slope ............................. Degree of deviation of a surface from the horizontal, usually expressed percent or a ratio of horizontal to vertical (i.e., 4:1).

Slot ................................ Perforations in plastic tubing. Also, the opening in the ground created by the trench less plow as it lays the tubing.

Spoil bank ................. Soil excavated from channel, ditch, or other site and placed along the excavation site.

Stretch ....................... The increase in length of the tubing caused by tension forces during installation. It is expressed as a percent increase of the length prior to installation.

Submain ...................... Branch drain off the main drain which collects discharge water from laterals or from the field.

Tile ................................. Drains made of burned clay, concrete, or similar material, in short lengths, usually laid with open joints to collect and carry excess water from the soil.

Tubing .......................... A flexible drain that gains part of its vertical soil load-carrying capacity by lateral support from the surrounding soil.

Watershed ............... Total land area above a given point on a stream or waterway that contributes runoff to that point.


Useful Conversion Factors


To convert         Into                  Multiply by
acres                   hectares            0.405
acres                   square feet        43,560
acres                   square meters   4,047
acres                   square yards     4,840
centimeters         feet                   0.0328
centimeters         inches               0.394
centimeters         meters               0.01
centimeters         yards                 0.0109
cubic feet            cubic inches      1,728
cubic feet            cubic meters     0.0283
cubic feet            gallons              7.48
cubic feet            liters                 28.3
cubic inches       cubic feet          0.00058
cubic inches       gallons              0.0043
cubic inches       liters                 0.0164
cubic meters       cubic feet          35.3
cubic meters       cubic inches      61,023
cubic meters       gallons              264.2
cubic meters       liters                 1,000
feet                     centimeters       30.48
feet                     inches               12
feet                     meters               0.305
feet                     yards                 0.333
gallons                cubic feet          0.134
gallons                cubic inches      231
gallons                cubic meters     0.0038
gallons                liters                 3.79
hectares              Acres                2.47
hectares              square feet        107,600
hectares              square meters   10,000
hectares              square yards     11,956
inches                 centimeters       2.54
inches                 feet                   0.083
inches                 yards                 0.0278
kilometers          feet                   3,281
kilometers          meters               1,000
kilometers          miles                 0.62
kilometers          yards                 1,094
To convert         Into                  Multiply by
Liters                  cubic feet          0.0353
liters                   cubic inches      61.02
liters                   cubic meters     0.001
liters                   gallons              0.264
meters                 centimeters       100
meters                 feet                   3.281
meters                 inches               39.37
meters                 kilometers         0.001
meters                 yards                 1.094
miles                  feet                   5,280
miles                  kilometers         1.61
miles                  meters               1,609
miles                  yards                 1,760
square centimeters                       square inches          0.155
square centimeters                       square meters          0.0001
square feet          square inches    144
square feet          square meters   0.0929
square feet          square yards     0.1111
square inches      square centimeters    6.45
square inches      square feet        0.007
square inches      square meters   0.00064
square meters     hectares            0.0001
square meters     square centimeters    10,000
square meters     square feet        10.76
square meters     square inches    1,550
square meters     square yards     1.2
square yards       square feet        9
square yards       square inches    1,296
square yards       square meters   0.8361
yards                  centimeters       91.44
yards                  feet                   3
yards                  inches               36
yards                  meters               0.914