GROUP: irrigation (ir)
DEFINITION: Irrigation and drainage ditches, sealed water storage, etc

1. Object
   1. irrigation & drainage ditch = anthropogenic channels constructed to conduct either irrigation or drainage water, or both.
   2. water storage tank = impermeable tank or basin designed to hold water.
   3. wellhead = well and surrounding area within clear edges caused by management of the well, such as a sealed area or a compacted animal track created by use of animal traction for water pumping.
   4. bridge (>2m) = transportation across water, with water surface underneath.
   5. retention pond = engineered basin, usually earthen, but sometimes a mix of surfaces and structures designed to hold and infiltrate water as part of a sealed surface drainage system. May include trees or other vegetation. Edges defined by basin top edge. Note: FORM = RP.
2. Modifier 1 (structure type)
   1. water storage tank
      1. open top = water surface >75% open to sky.
      2. covered = <25% of water surface open to sky.
3. Modifier 2 (of building footprint)
   1. local roads, paths, & access
      1. wide >2 m

1. irrigation & drainage ditch
   1. permeable = earth
      1. wide (>2m) = ir01
   2. sealed
      1. wide (>2m) = ir02
2. water storage tank
   1. open top = water exposed
      1. small (<30m) = ir03
      2. large (>30m) = ir04
   2. covered = water covered by a permanent cover.
      1. small (<30m) = ir05
      2. large (>30m) = ir06
3. wellhead
   1. permeable = ir07
   2. sealed = ir08
4. retention pond = ir09

1. IF TYPE with greater area is very similar or otherwise unclear:
   1. Choose permeable over sealed.
   2. Choose open top over covered.
2. IF feature includes a pump house with water tank:
   1. IF >50% area is water tank or the water tank area is similar to the pump house area, then classify as ir.
   2. IF clearly <50% of feature is water tank, then use GROUP = nb.
3. IF paralleled by a <2 m transportation feature, and unclear which has greater width or feature area:
   1. Choose transportation over irrigation.

FORM:

USE:

COVER:

TYPE: