Unit of competency Outline

Date retreived
23/07/2026 9:52 AM AWST

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Design drainage systems

Design drainage systems

Unit of competency
National Code
AHCDRG501A
State Code
D6812
TGA Status
Replaced
DTWD Status
Replaced
Current Release Number
1.00
Current Release Date
10/06/2011
View on TGA
State Implementation and Classification
Approved Date
03/09/2013
Field of Education
030907 - Water And Sanitary Engineering
Original Release Date
03/09/2013
Nominal Hours
50
Description
This unit covers the process of identifying design requirements, determining specifications for drainage systems, and designing drainage systems and defines the standard required to: develop specifications for water transfer, recharge, reuse and harvesting systems; assess the requirements for pumping capacity in a drainage system and power requirements; identify performance indicators for the drainage system; predict volumes and rates of surface run-off and system leakage; design a drainage system that factors in the characteristics of the irrigated landscape and soil.
Notes
Elements and Performance Criteria
1. Determine design requirements
  • 1.1. Water transfer, recharge, reuse and harvesting systems are designed to conserve natural resources.
  • 1.2. The process of collecting or storing water does not degrade the water quality for the enterprise or the environment.
  • 1.3. Construction specifications define the work required to make suitable water available to the enterprise in accordance with environmental and Occupational Health and Safety (OHS) requirements.
  • 1.4. Environmentally sensitive areas are identified and protected according to local, State and National legislation.
  • 1.5. Design calculations and decisions are documented to enterprise requirements.
2. Define pumping and power systems
  • 2.1. Pumps are selected to move water efficiently when needed to water storage or treatment, at the flow and pressure required to design specifications.
  • 2.2. The pump motor combinations are efficient, and the pumps are reliable, functional, serviceable and flexible for the intended application.
  • 2.3. Energy requirements are determined, and layout of electricity lines are determined and checked with local authority.
  • 2.4. The relationship between capital and operational costs are optimised including a comparison of energy sources.
  • 2.5. Structures, valves and accessories are selected and integrated into a functional system that can be monitored and maintained according to enterprise guidelines.
  • 2.6. Performance indicators, design calculations and decisions are documented according to enterprise guidelines.
  • 2.7. Construction specifications define work required to make suitable pumping and power system available to enterprise.
  • 2.8. Power supply design specification is checked with power authorities.
3. Design a drainage system
  • 3.1. Regional geology and geography is investigated to predict drainage parameters.
  • 3.2. Site investigations to assess depth of clay, depth of ground water, soil and water salinity, and structural or chemical impediments are used to determine the most cost effective drainage system.
  • 3.3. Predictions of leaching fractions and salt movements are documented, and soil amelioration and drainage management plans are developed.
  • 3.4. The need for leachate interception and dewatering system is determined and if required, construction specification prepared for interception and collection, disposal, reuse or recycle.
  • 3.5. Drains and structures are capable of carrying the design water volumes and intensities according to enterprise standards.
  • 3.6. Damage from water logging is minimised according to enterprise standards.
  • 3.7. Hydrological calculations predict volumes and rates of surface run-off according to enterprise standards.
4. Determine capital expense budget
  • 4.1. Design calculations and decisions are documented and relevant information is communicated clearly through plans, specifications and manuals.
  • 4.2. Design output is checked by a competent designer against enterprise objectives.
  • 4.3. Materials requirements are determined and documented from plans and specifications.
  • 4.4. Labour requirements are estimated based upon documented work schedule with reasonable allowance for variances in work schedules.
  • 4.5. Costing attributed to each component is based upon quoted information from suppliers, or sound analysis of individual elements.
5. Determine operating expense budge
  • 5.1. Operating expense budget indicates all expenses applicable to the completed drainage system.
RANGE STATEMENT
The range statement relates to the unit of competency as a whole.
Irrigation system types may include:
flood
furrow
micro-sprinklers
pop-ups
impact sprinklers
low-level lines
overhead sprinklers
drippers
micro-jets.
Irrigated systems may involve:
water harvesting
delivery
drainage collection
drainage storage and treatment as well as natural drainage and treatment systems involving the removal of pollutants through evaporation, and/or clearance by filtration through surface layers.
EVIDENCE GUIDE
The evidence guide provides advice on assessment and must be read in conjunction with the performance criteria, required skills and knowledge, range statement and the Assessment Guidelines for the Training Package.
Overview of assessment

Critical aspects for assessment and evidence required to demonstrate competency in this unit
The evidence required to demonstrate competency in this unit must be relevant to workplace operations and satisfy holistically all of the requirements of the performance criteria and required skills and knowledge and include achievement of the following:
develop specifications for water transfer, recharge, reuse and harvesting systems
assess the requirements for pumping capacity in a drainage system and power requirements
identify performance indicators for the drainage system
predict volumes and rates of surface run-off and system leakage
design a drainage system that factors in the characteristics of the irrigated landscape and soil.
Context of and specific resources for assessment
Competency requires the application of work practices under work conditions. Selection and use of resources for some worksites may differ due to the regional or enterprise circumstances.
Replaces
State Code National Code Title Type
S3461 RTE5607A Design drainage systems Unit of competency
Replaced By
State Code National Code Title Type
BAT31 AHCDRG501 Design drainage systems Unit of competency