To improve the longevity of permanent reference marks (PRMs), Toitū Te Whenua can supply plastic survey mark boxes and covers. The box and cover sets are made of durable plastic with ‘survey mark’ printed on the lid. These are similar to the products used by utility companies and territorial authorities to cover water tobies.
Protective black plastic box installed flushed with the ground over a geodetic mark. BWPM mark in Waiuku.
These plastic boxes are far cheaper than cast iron products but offer a similar degree of protection. Note that plastic boxes and covers aren’t suitable for installation on roadways or in other high-traffic areas.
Surveyors can order survey mark covers by contacting Mark Dunnett at Survey Services (HB) Ltd on 06 844 4354, or at mark@surveyhb.co.nz
For information email us at crm_geodetic@linz.govt.nz with the subject line 'Geodetic - survey mark covers'.