Woods became involved with the Pegasus Town project after considerable preliminary work had been completed. During our initial site visit we raised concerns as to how much physical topographical survey had been undertaken due to the density of vegetation on the site. Subsequent investigation revealed that only a portion of the site had in fact been surveyed and that a large part of the information being used for decisions was based on questionable digitized data of indeterminate origin.

Woods expressed concern at the risk involved in proceeding on this basis and given that design work had to start before the clearing of the site would take place, we suggested that LIDAR survey data for the site be purchased from Environment Canterbury. LIDAR is a cost effective alternative to conventional ground surveying for medium to large scale terrain modelling projects and is able to obtain accurate survey data even on heavily vegetated sites. This resolved timing constraints and allowed design work to proceed with much improved data improving decision making and consequently improving costings.

Due to the scale of the project, carrying out a monthly field survey across the whole site was problematic and posed a significant health and safety issue for field staff given the amount of plant being employed on site. Woods therefore implemented the use of LIDAR for earthworks control. Data was collected on a regular basis across the whole site within a half day at comparable cost to field survey, but with considerable benefits in getting an accurate snapshot of the site at a given point in time without risk to personnel. Field checks on areas of works confirmed accuracies suitable for volume control.

The use of regular LIDAR surveys was subsequently put in place and have been undertaken at benefit to the client with survey accuracies being proven over time to be comparable to field surveys.

Woods are one of New Zealand's biggest users of this technology as we also use LIDAR for accurate flood modelling, road and engineering design as well as for urban planning.