Rivers and Streams Monitoring

Application Notes

Application Background                                                                                                                                      Printer Friendly Version

Careful measurement and monitoring of streams and rivers is vital to manage water resources throughout the world. Rivers also flood so the careful measurement of river levels is vital to manage damage during floods.

Rivers and Streams Monitoring

River flow measurements are calculated by hydrographers and are analysed by hydrologists and other scientists. To calculate flow, the river level is measured accurately at a certain point in the river, typically at a flume or weir which has known dimensions / has been constructed to a known standard. There are different types for different conditions, for example a flume type generally passes sediment more easily, while a V notch type is more difficult in waters with sediment.

Water Level Monitoring-Water Level Instrument
Water Level Monitoring-Still Well
Water Level Monitoring-Methods

The water level above the low point of the flume or weir is measured and the flow is calculated based on the shape / size of the flume or weir and the level of water passing through that flume or weir. When large / wide rivers need to be measured, there is a manual river gauging process undertaken where the flow and velocity and level at several points and depths are measured by hydrographers (this is called a river gauging) and a set of relationships is determined such that the flow at a certain point in the river can be determined based on the level at a certain point in the river (stage to flow relationship).

Application Detail

There are several different methods used to measure streams and rivers, and these methods will be summarized below. The measurement of rainfalls is often associated with river measurement stations as local rainfall is a key factor especially in hills or mountainous areas.

Rivers and streams monitoring

Regular reporting of river levels to a central server allows authorities to monitor stream and river flows across a country or region and use that date for immediate use purposes. For example: flood alerts / flood warnings as well as longer term analysis by hydrographers and hydrologists to manage the rivers/catchments in the long term.

Rivers and Streams Monitoring Installation

The measurement methods include:

  • Method 1 – a still well or still pipe with a shaft encoder / float and wheel / beaded float line system
  • Method 2 – a pressure sensor which is immersed into the stream or river
  • Method 3 – the more complex pressure bubbler system which allows for a small open tube to be immersed into the stream or river with a gas pump or gas cylinder to inject small bubbles into the open tube and measure water depth by measuring the back pressure required to force bubbles out of the tube in the water

There are also emerging technologies such as radar and ultrasonic which can be used to measure water depth.
While there are many methods / technologies available, the most common and the most stable method is the shaft encoder float and wheel system. This method required a large well or a smaller pipe to be installed on the stream or river bank or on a bridge structure to provide a stable / not disturbed by flow or wind measurement environment for a small float, a float line and a counter weight so the movement in stream / river level can be measured by rotation of the shaft of a wheel. Typically the shaft rotation is measured very accurately by light or laser encoder, and the data is shown on the display and is recorded in the data logger within the instrument.

Water Level Monitoring - 6541C Precision Water Level Instrument

The Unidata 6541C Precision Water Level Instrument is a very accurate shaft encoder instrument, which has an LED display for the water level, as well as an internal data logger so water level readings can be recorded every 1, 5 or 10 minutes as required.

When a Neon Remote Terminal or Module is added, the water level information can be transmitted over the internet to a central Neon server to allow authorities view the data on the web in near real time.

Typical Configuration

Options for Application Specific Instruments / InputsUnidata Part NumberDescription
Ultrasonic Doppler Instrument - Velocity and Depth6526H-21Starflow Ultrasonic Doppler Instrument 0-2m
Ultrasonic Doppler Instrument - Velocity and Depth6526H-51Starflow Ultrasonic Doppler Instrument 0-5m
Water Level Instrument6541C-11WLI with 500mm Pulley & Alk Batt Metric (Imperial version available)
Float6541F-115WLI Float - Cylinder 115mm (other options available)
Float Line6541D-MWLI Beaded Floatline Metric (Imperial version available)
Options for Neon Telemetry - NRT / RTU / Field UnitsUnidata Part NumberDescription
Cellular RTU 3G2013F-AB03Neon Metering Module 3G with Antenna and Li Battery
Cellular RTU 4G2013F-AB04Neon Metering Module 4G with Antenna and Li Battery
Cellular RTU 3G - Industrial2016F-AB03Neon Remote Terminal 3G with Antenna and Li Battery
Cellular RTU 4G - Industrial2016F-AB04Neon Remote Terminal 4G with Antenna and Li Battery
Low Earth Orbit Satellite Globalstar2015E-AB0Neon Remote Terminal - Satellite Globalstar Modem with Antenna and three Li Batteries
Ethernet2017E-0B0-1 or 3NRT Ethernet with single or triple Ethernet Ports
with three Li Batteries
Equatorial Orbit Satellite - Inmarsat2018E-AB0-1 or 3NRT Ethernet with single or triple Ethernet Ports
with three Li Batteries
LCD Display2500ENRT LCD Display
NRT Field Termination Strip2103F2015E,2016F,2017E, and 2018E NRT FTS
NRT Firmware Option2303A-8M8M Extended Memory Option
NRT Firmware Option2303A-8M-CAM8M Extended Memory & Serial Camera Option
NRT Firmware Option2303A-CAMSerial Camera Option
Options for Neon Application Software - Customer ServerUnidata Part NumberDescription
Neon Application Software2302ANeon Server Software Licence Incl 5 NAL
Neon Application Software2302A-10Additional 10 NRT Access Licences
Neon Application Software2302A-20Additional 20 NRT Access Licences
Neon Application Software2302A-50Additional 50 NRT Access Licences
Options for Neon Application Software - Unidata ServerUnidata Part NumberDescription
Neon Application Software2301ANeon Data Initial Subscription Setup Fee
Neon Hosting Service2301A-01Neon Data Service Fee for 1-50 NRTs
Neon Hosting Service2301A-02Neon Data Service Fee for 51-100 NRTs
Neon Hosting Service2301A-10Neon Data Service Fee Metering
Options for Conventional Dataloggers / Field UnitsUnidata Part NumberDescription
Standards Starlogger6004D-11Red Logger 512K with Alkaline Battery
Display Starlogger6004D-21Blue Logger 512K with LCD and Alkaline Battery
Prologger7001D-11Green Logger 1M with LCD and Alkaline Battery
Micrologger8010C-EURMicrologger 512K
Starlogger Field Termination Strip6103E6004D FTS
Prologger Field Termination Strip7100E7001D FTS
Starlog V4 Management Software6308A-AUEStarlog V4 Full Licence Key