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PHOTOGRAMMETRY FOR THE SNOWY MOUNTAINS SCHEME 
by Dipl. Ing. W. A. G. Mueller, M.I.S.(Aust.) 
INTRODUCTION 
THE Snowy Mountains Scheme, the largest engineering project ever undertaken in 
Australia, is being constructed 
(a) to produce Hydro-electric power to meet increasing demands for industrial 
expansion, and 
(b) to provide /rrigation water for the dry inland plains in order to increase 
food and other primary production. 
This involves the construction of 10 major dams, 12 power stations, 100 miles 
of diversion tunnels, shafts up to 1,100 feet deep, and hundreds of miles of mountain 
roads, aqueducts, and transmission lines through rugged alpine country. 
The investigation, planning, design and construction of such a scheme, embrac- 
ing an area of some 3,060 square miles, requires surveyinz and mapping of consider- 
able scope and variety. 
Surveying and mapping provides the basic information for the design of any 
engineering project. The larger the project the more complex will be this basic 
information often involving geodetic surveys of highest accuracy. 
Nowadays, when the designing engineer makes use of advanced methods and 
modern materials—such as photo-elasticity and prestressed concrete—surveyors can no 
longer plod along the ground with a plane table or tacheometer. Not that they 
must be regarded as obsolete, but being confronted with a project of the magnitude 
of the Snowy Scheme more economic techniques, more efficient instruments and 
very often more accurate surveys are required. 
The Snowy Mountains Authority, recognising the importance of Speedy and yet 
reliable surveys, provided the latest, most improved tools and instruments to carry 
out the job accurately and economically. The photogrammetric equipment, repre- 
senting an investment of more than £30,000 forms one section of this modern range 
of surveying instruments held by the Authority. 
GENERAL MAPPING 
When the Snowy Mountains Authority was established on the 1st August, 1949, 
field investigation commenced immediately. However, at this stage the proposed 
scheme was based on limited survey information and a few spot heights only. 
Large scale topographical maps did not exist. 
It was realised that the most urgent need for such maps could be met by 
aerial photogrammetry only. Whilst the first surveyors appointed by the Authority 
obtained the necessary ground control, contractors supplied a 50 ft. contour map 
at a scale of 4 inches — 1 mile, compiled on a Multiplex machine from aerial 
photographs taken at 25,000 feet altitude with a Williamson Eagle IX, 6 in. camera. 
Each compilation sheet covered an area of 8 miles by 4 miles. 
Due to adverse climatic conditions the aerial photography took three summer 
periods (Nov. 51- Dec. 53) to cover an area of 5,400 square miles with 35 flight 
strips of approximately 50 miles length each. The plotting of specified priority 
areas comprising 3,000 square miles was completed by the beginning of 1954. 
FURTHER MAPPING REQUIREMENTS 
This General Map—known as the "SMA 4 Inch Series"—covering the overall 
area of the scheme, served for preliminary studies for the location of dams and 
power developments. 
From these investigations the most favoured schemes were then examined in 
more detail necessitating maps and plans of a more detailed nature. 
This step called for large scale aerial photographs from low altitudes 
(a) for the compilation of 10 ft. contour maps at a scale of 200 ft. - 1 inch 
for specified areas. such as damsites, for the derivation of storage 
capacities, for road and campsite locations, and for geological base 
maps, 
(b) for photo interpretation under a steroscope by geologists, for the study 
of proposed quarry sites and for soil conservation measures. 
ANNEXURE D