Waterman floods the UK - Waterman Civil & Transportation Group

ClientEnvironment AgencyLocationUnited Kingdom
ConsultantWaterman GroupContractorRichard Russell

Project Summary

Waterman Civil & Transportation Group (WCT) was one of the original 12d Model software users in the UK and have finalised an initial study for a housing development of 3000 homes at Waterlooville on the South Coast of England.


The Challenge

This study involved a detailed assessment of flood risk in the area. The Environment Agency had done rough flood outlines based on a 50m grid using the Flood Studies Report, but a detailed assessment was required for planning to determine the existing flood plain and to compare this with another ‘post development' flood study.


The Solution

For cost and speed, aerial photogrammetery was ordered to cover the entire site and local surveyors were used to locate the property boundary using traditional means. The resultant photogrammetery (dgn format) and boundary (dxf format) were merged into a single 12d digital terrain model of several hundred thousand points.

To obtain finer detail of the river and to verify the model of the plain, further detailed river cross sections were then surveyed. In the office, work began on building the HEC RAS project inside 12d Model.

After ensuring concurrence on hydrological methodologies with the local Environment Agency office, WCT carried out the back water hydraulic study. Graduate Engineer and 12d user Richard Russell said, “Using 12d with HEC RAS I was able to devote more time to sensitivity tests in HEC RAS and in 12d. I had the luxury of time to try different roughness coefficients and to test if ground cover picked up with the photogrammetery had a significant impact on the results. This gave us better confidence in the final results”.

In addition to creating the HEC RAS project, 12d Model was used to present the water level results. Detailed drawings were produced for submission to the Environment Agency. Internally the visualisation abilities in 12d allowed quick checking at all stages including the final water levels.

Project Director for WCT, Stuart Aldridge, commented, “12d cut the time taken for this type of study significantly. This was the first time we had used 12d for flood modelling and we were very impressed.

“Previously, significant resources were devoted to what I now view as laborious and unnecessary data entry. We also get to use survey data at a much earlier stage, which is proving useful on such a big development. We still propose a detailed survey for a later date, but for now our client can defer the significant cost of the survey until much later.”

The Result

While WCT and their client were benefiting from using 12d Model on this project, the two other parties involved also had the opportunity to see 12d in action on a live project. Although both have different interests and uses for 12d, surveyors Julian Brotherton & Partners and the Environment Agency were both impressed with 12d’s quick manipulation of data and 3d abilities. Within a few months both parties became 12d users themselves.

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