Survey Mark Protection.

[Mark Geddes]

Has anyway seen an improvement in the level of survey mark protection in the last couple of years?  There was a lot of talk about it in 2012 and some advances were made to local councils on the basis that they let some of the civil works contracts and could enforce survey mark protection on their contractors.  The ultra-fast broadband roll-out for example has seen the demise of many survey marks unnecessarily. 

While GPS methods and the use of adopted connections does mean that a lesser number of marks or a different selection of marks may be used for a cadastral survey now compared with conventional methods of the past, I still think much of the needless loss of marks could be avoided with care and education of contractors and other operators.  Those who do geodetic survey work and know the ins and outs of mark selection and have greater experience in a wider region of the country would know more than I, but I haven't seen an improvement and with no prosecutions for removing survey marks since the Act came in I think more needs to be done.  Do any councils have rules on this?  Is anyone aware of whether it is becoming standard in contracts in their area?

If others still see this as an issue could this be a project for the ICS maybe?  It may have costs associated with it and no direct earning power, but it may avoid more awkward surveys and additional cost to our clients.

[Pat Sole]

It has always been an issue and will continue to be - I have just reported to LINZ a watermain project in New Plymouth that has possibly/probably seen the loss of marks on our local 50 year old EDM test base in New Plymouth (probably one of a half a dozen in the country - which raises another question, how are surveyors callibrating their total stations). These marks may not have cadastral value, but are very valuable as the distances are known very accurately by analysis of successive measurements by differing equipment etc over the years. I am awaiting what LINZ are to do about it (but suspect the value of these marks may have already been lost!). Surveyors need to report to LINZ when they suspect mark disturbance/destruction, and LINZ need to act quickly and forcefully on that advice. Unfortunately, loss of more marks is a direct result of LINZ centralisation, though be4udig is generally a good advancement.

[Brent George]

This is another "on-going issue".

There are existing mechanisms in place that try to address the needless destruction (or lack of protection) of marks. These include the 'before-u-dig' (www.beforeudig.co.nz/#) service and also the LINZ Mark Protection (www.linz.govt.nz/data/geodetic-system/geodetic-control-network-development-maintenance-and-protection/report-damage-or-disturbances-survey-marks) process.

Of course, these types of systems are only as good as the whole process.  The flagging of the marks to a contractor is one aspect, but an important part is the policing of the protection after the fact.  That is to say, "was the mark sufficiently protected as required". 

I also recall many attempts at getting Councils and Developers involved in the process - to convince them that the works they let need to account for the important survey marks that may be affected.

I recall attempts at trying to make the contractors aware of the importance of survey mark protection.  (But the message often does not get to the digger driver...)

I even recall a story in the 1980's where an attempted prosecution of a contractor for destruction of a survey mark was not pursued simply because no-one actually saw the mark being destroyed. ie:  Just because it was there on Monday and not Wednesday does not mean that the contractor digging trenches at the mark on Tuesday destroyed it....

We have completed a small number of protection works where a geodetic mark about to be destroyed is replaced by another.  We have also been involved in post earthquake SCIRT Mark Protection, and subsequent LINZ Mark Protection surveys here in Chch.  These are token efforts. 

There is a perception that GNSS will enable efficient replacement of geodetic marks these days (as opposed to protecting historical marks).  This perception trickles down to cadastral marks, and with the pseudo coordinated-cadastre LandonLine database available the perception that marks are expendable will continue.

... until there is an earthquake or there are no marks remaining in an area....