C—lA

In accordance with instructions received from the Public Works Department, the Department has determined the precise alignment of the proposed Rimutaka Tunnel and also commenced a precise levelling traverse. The alignment was finalized by breaking down from the existing geodetic triangulation station. Six miles of the twenty-two miles of juke precise levelling was completed by the end of January, 1947. Owing to staff shortage, this work has since been held up.

Topographical Mapping The following tables show the progress made in topographical mapping to date: 1:25000 Series

The only field-work completed in this series is special mapping carried out in the Otago District in connection with mining and forestry developments in the Kaitangata and Balclutha locality covering an area of 410 square miles. This work will be plotted at Head Office. One drawing of a Wellington sheet was published during the year.

1:63360 Series

Last year's returns are shown in parentheses. Two small parties located in Central Otago and the Thames districts were operating for part of the year. Only 162 square miles were mapped during the year when operations were closed down and staff diverted to other urgent work. It is regretted that it has become necessary to close down this work, which is of such vital importance to national development. The series are in great demand by all State Departments, serving as a basis for many large development projects. REGIONAL AND WORKS PLANNING A small staff at Head Office have proceeded with the preparation of regional survey data, and as a result a number of series of transparencies of population and land slopes have been completed. All districts are preparing holding-maps and schedules illustrating the extent of land held under individual ownership throughout the Dominion. The work was well advanced at the end of the year, and when completed will be used in connection with land-settlement purchase.

8

— Area (Square Miles). Number of Sheets. \ Maps published as at 31st March, 1946 Maps published during year Mapping in hand 1,100 15 1,725 28 1 33 Totals 2,840 62

North Island. South Island. Total. Area (Square Miles). Number of Sheets. i Area (Square Miles). Number of Sheets. Area (Square Miles). Number of Sheets. Published at 31st March, 1946 Published during the year .. Drawings completed Mapping in hand 17,450 150 436 •6,245 69 1 1 21 24,100 1,568 436 2,946 77 5 1 12 41,550 1,718 872 9,191 146 6 2 33 Totals 24,281 (24,181) 92 (92) 29,050 (27,770) 95 (93) 53,331 (53,169) 187 (185)