Assessor Resource

NWP421A
Collect, measure and process hydrometric stream discharge gauging

Assessment tool

Version 1.0
Issue Date: March 2024


This unit supports the attainment of skills and knowledge required for assistant hydrographers, field hydrologists and water operators responsible for reporting water quality, volume and flow in water systems. This unit is part of the skills set for hydrography and is suitable for entry level and working under the supervision of a senior hydrographer.

This unit describes the competencies required to collect data using a range of discharge measuring methods and equipment, measure and calculate readings and interpret and report data for a range of clients and stakeholders.

You may want to include more information here about the target group and the purpose of the assessments (eg formative, summative, recognition)

Prerequisites

Not applicable.


Employability Skills

This unit contains employability skills.




Evidence Required

List the assessment methods to be used and the context and resources required for assessment. Copy and paste the relevant sections from the evidence guide below and then re-write these in plain English.

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.

Critical aspects for assessment and evidence required to demonstrate competency in this unit

The candidate should demonstrate the ability to collect data using a range of discharge measuring methods and equipment including:

measuring and calculating readings

interpreting and reporting data for a range of clients and stakeholders

gathering data related to client requirements

interpreting complex documentation and applying it to the specification of hydrometric data collection and reporting procedures

sampling accurately and consistently with client requirements

analysing and verifying data using standard procedures, software and databases

preparing clear and accurate reports

storing and archiving data

identifying, reporting and (within scope of job function) solving potential or current problems.

Context of and specific resources for assessment

Access to the workplace and resources including:

documentation that should normally be available in the workplace

workplace specific equipment and technology

supervision and experienced team members to provide observations, feedback and third party reports

enterprise operating procedures and work allocation

relevant codes, standards, and government regulations.

Where applicable, physical resources should include equipment modified for people with disabilities.

Access must be provided to appropriate learning and/or assessment support when indicated by gaps in competency.

Assessment processes and techniques must be culturally appropriate, and appropriate to the language and literacy capacity of the candidate and the work being performed.

Validity and sufficiency of evidence require that:

competency will need to be demonstrated over a period of time reflecting the scope of the role and the practical requirements of the workplace

where the assessment is part of a structured learning experience the evidence collected must relate to a number of performances assessed at different points in time and separated by further learning and practice

a decision of competence should only be made when the assessor has complete confidence in the person's competence over time and in various contexts

all assessment that is part of a structured learning experience must include a combination of direct, indirect and supplementary evidence

where assessment is for the purpose of recognition (RCC/RPL), the evidence provided will need to be authenticated and show that it represents competency demonstrated over a period of time

assessment can be through simulated project-based activity and must include evidence relating to each of the elements in this unit.

In all cases where practical assessment is used it will be combined with targeted questioning to assess the underpinning knowledge. Questioning will be undertaken in a manner appropriate to the skill levels of the operator, any cultural issues that may affect responses to the questions, and reflecting the requirements of the competency and the work being performed.


Submission Requirements

List each assessment task's title, type (eg project, observation/demonstration, essay, assingnment, checklist) and due date here

Assessment task 1: [title]      Due date:

(add new lines for each of the assessment tasks)


Assessment Tasks

Copy and paste from the following data to produce each assessment task. Write these in plain English and spell out how, when and where the task is to be carried out, under what conditions, and what resources are needed. Include guidelines about how well the candidate has to perform a task for it to be judged satisfactory.

Required skills:

use area velocity method

assess hazards and apply relevant precautions and action

estimate and explain the anticipated vertical distribution

make calculations on depth and velocity

maintain the integrity of measurements

use a range of suitable techniques to accurately determine mean stage in rapidly changing situations

adjust measurements correctly

plot discharge measurements on organisation's preferred scale

use formulae for determining the percentage deviation

use computing system and software to transfer calculated flows to office database

assemble and test metering equipment

check operation of equipment

check gauging section

set tag lines

prepare gauging section.

Required knowledge:

principles of discharge measurement

methods for calculating mean velocity in a vertical

methods for determining the cross sectional area at a site

alternative methods of discharge measurement

the organisation's operating procedures for hydrometric stream discharge measurement

the timing, location and number of verticals for stage readings

the characteristics of a suitable section for wading and boat gauging and how to make modifications

requirements for surface, single and multipoint floats

basic mathematical principles for area and velocity measurements

correction procedures for horizontal angles

correction procedures for suspension measurements

techniques for monitoring stage changes during discharge measurement

weighted mean stage calculations

discharge and mean stage adjustment

technical components in calculating discharge

factors impacting on discharge measurements and the quality of the discharge

formulae to adjust gaugings

potential impacts of modifications of site, method or equipment on discharge accuracy

confidence limits

function of each field on the measurement forms

the organisation's registration procedures

calibration procedures

OHS procedures, safe operation of equipment and identification of potential hazards.

The range statement relates to the unit of competency as a whole. It allows for different work environments and situations that may affect performance. Bold italicised wording, if used in the performance criteria, is detailed below. Essential operating conditions that may be present with training and assessment (depending on the work situation, needs of the candidate, accessibility of the item, and local industry and regional contexts) may also be included.

Factors affecting accuracy may include:

laminar flow

turbulent flow

critical states

sensitivity

pulsing

backwater.

Gauging methodologies may include:

wading

travellerway

cableway

boat

bridge

portable flume

float

acoustic profiler.

Area velocity method may include:

AS 3778 - Measurement of Water Flow in Open Channels:

velocity-area methods

measurement by current-meters and floats

operating procedures for discharge measuring equipment and calibration.

Hazards may include:

boat handling

bed stability

winch operation

tag line setting

traffic management

working at heights

manual handling

personal protective equipment (PPE).

Occupational health and safety requirements will include:

hazard recognition:

working on and near water

safe working depth

bank and bed stability

rising stage

snags

floating debris

water temperature

water contamination

weather exposure

rescue procedures

PPE requirements:

onsite communication and procedures for working remotely

equipment

storage

assembly

cleaning

handling, transport

personal welfare and safety:

medical constraints

CPR

First Aid

water survival and rescue

self rescue

bush survival

4WD driving and recovery

defensive driving

boat handling

traffic management authority regulations.

Gauging equipment may include:

winch

travellerway

cableway

boat

vehicle

trolley mount

mechanical & acoustic meters

oil change

calibration.

Gauging site conditions may include:

hazards

obstructions

climatic

sufficient depth

sufficient velocity

flow angle

laminar flow

bank condition

anabranches and multiple channels

pre-season maintenance.

Alternative methods may include:

volumetric

flumes

slope/area techniques

dilution.

Required mathematical techniques will include:

area

volume

mean

suitable formulae

trigonometry.

Percentage deviation will be determined by:

checking:

calculations

equipment

control

recording equipment

repeat measurement.

Supporting information will include:

gauging section location and access maps

photographic records

site preparation undertaken

comments on issues encountered.

Organisational requirements will include:

data management and reporting

worksite procedures

occupational health and safety procedures

operating procedures.

Copy and paste from the following performance criteria to create an observation checklist for each task. When you have finished writing your assessment tool every one of these must have been addressed, preferably several times in a variety of contexts. To ensure this occurs download the assessment matrix for the unit; enter each assessment task as a column header and place check marks against each performance criteria that task addresses.

Observation Checklist

Tasks to be observed according to workplace/college/TAFE policy and procedures, relevant legislation and Codes of Practice Yes No Comments/feedback
Identify stream discharge and factors affecting accuracy. 
Identify the purposes of gauging and gaugingmethodologies. 
Identify the area velocitymethods for calculating discharge. 
Identify hazards and hazard management principles according to occupational health and safety requirements. 
Take measurements during gauging following occupational health and safety procedures. 
Select verticals for measurement of velocity. 
Select suitable gauging equipment according to the conditions of the location, assignment and client requirements and gauging site conditions. 
Prepare the equipment and gauging site. 
Apply a range of suitable and alternative methods for obtaining the mean velocity in a vertical. 
Apply the mid section and mean section methods. 
Position the current meter according to guidelines. 
Select the appropriate discharge measurement method. 
Calculate the depth settings and point velocity using required mathematical techniques. 
Apply corrections for oblique flows and drift angles. 
Calculate the mean velocity for each vertical. 
Calculate the area and discharge corresponding to each sub-section. 
Calculate the discharge using the mid section and mean section method. 
Calculate and record the mean stage and rate of change. 
Calculate the channel storage and time of travel effects. 
Compare the discharge measurements with the current rating. 
Record the percentage deviation from the rating. 
Grade and record the gauging quality with interpretation comments. 
Gather supporting information from the site and document accurately according to organisation requirements. 
Enter gauging into ratings database according to organisation requirements. 

Forms

Assessment Cover Sheet

NWP421A - Collect, measure and process hydrometric stream discharge gauging
Assessment task 1: [title]

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Assessment Record Sheet

NWP421A - Collect, measure and process hydrometric stream discharge gauging

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Assessment task 1: [title] Result: Competent Not yet competent

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