NATIONAL OCEANOGRAPHIC PROGRAM—1965 397 
of Northern and Northwestern Lakes have included as part of their stated 
purpose the investigation of lake levels. 
Since 1898, extensive series of measurements have been made by the Lake 
_ Survey in the natural lake outlet rivers and formulae have been determined 
for computing the lake Sutrlows from the observed water levels. The Lake 
Survey publishes outflow data covering the period from 1860 to date. 
The Lake Survey furnishes technical advice to the Division Engineer, NCD, 
pertaining to the Division Engineer's International Board activities, includ- 
ing those of the International Lake Superior Board of Control, the International 
Niagara Board of Control, the International Niagara Committee, and the Inter- 
national St. Lawrence River Board of Control. The Lake Survey has developed, 
or participated in international development of; various plans for regulation 
of the Great Lakes. 
In 1959, the Lake Survey was assigned a civil works investigation project 
CW-181 titled, Lake Hydrology Studies. The project is for the purpose of sun- 
marizing available information pertaining to Great Lakes hydrology and improv- 
ing present methods of estimating and forecasting Great Lakes water supply 
and hydrologic effects. 
The Pecaentred mission of the Lake Survey today is to collect, correlate, 
analyze, and make available in usable form to all interested agencies physical 
data relating to the water resources of the Great Lakes. Examples of physical 
. data assembled in usable form by the Lake Survey Tieerics emadee water levels 
‘and depths, current velocities, cies Glare water supplies to the Great Lakes, 
temperatures, topography, hydrography, crustal movement, littoral drift, shoal- 
ing and sedimentation, geodetic positions, wind velocities, and ice formation 
and related phenomena, 
