River Colne & Holme Tributary Survey

Study:

Check survey of over 40km of rivers including the River Colne, Holme and New Mill Dike that had previously been surveyed in 2005.

This survey was to be used to quantify any elevation changes associated with the previously surveyed areas. Existing control stations used on the previous survey would also be checked to an E6 grade specification.

Client Requirements:

Channel Cross Sections & Hydraulic Structures in AutoCAD format. Surveyed at requested locations, presented with Hard & Soft Bed.
Long Section profile surveyed through any requested weirs and shown in AutoCAD format.
All Cross Sections surveyed using existing 2005 naming system.
Data outputted in EACSD, ISIS & XYZ format.
Survey report and photographs of each Cross Section. Each photograph named with the Cross Section name and a description.
Checks on existing Control Stations used in the 2005 survey, surveyed to E6 grade specification.

Survey & Deliverables

Preparation

As this was a check survey, there would be a larger distance between the cross sections – therefore driving routes were planned between each location.
Ensuring access was arranged before visiting site was essential as a lot of time could be wasted if staff could not carry out a cross section survey on arrival.
All cross section locations were uploaded onto the GNSS Receiver.
Weather warnings were checked regularly leading upto this survey due to the time of year and nature of the watercourses.
A site specific Risk Assessment and Method Statement was prepared for this project to ensure safe working practices.

Collecting the data

Hydraulic structures and hard detail was surveyed as a comparison to previous 2005 survey.
A combination of GNSS Receiver and Total Station techniques were utilised to carry out the check survey.
Survey data was downloaded and stored at the end of each day and checked to ensure no information had been overlooked.
Safe practices were carried out at all times and the prepared Risk Assessment and Method Statement were adhered to throughout.
Checks were deployed on the existing control stations using a GNSS Receiver stabilised with a bipod.
Progress reports sent to client at the end of each week. Schedule for following week included.

Processing

Data outputs included ISIS & EACSD.
A report was produced with a comparison table showing differences between existing control station coordinates & new Precision Point Surveys coordinates.
Cross Sections were presented in AutoCAD format.
Gauge Board description sheets produced for all Gauge Boards surveyed on the watercourses.
In-house processing procedures followed to maintain consistency.
Independent checking system carried out.