Page:John Nolen--New ideals in the planning of cities.djvu/70

NEW IDEALS IN THE PLANNING OF against the bulkhead and to accommodate a line of river or canal craft both inside and outside the vessel when so moored. Space should also be available for vessels to pass with ample clearance in the remainder of the waterway. This means that between bulkhead structures a width of about eight times that of the normal vessel should be maintained as the total space available, and that a width of four times the normal vessel beam should also be maintained in the fairway.

Real estate on upland being so much more valuable than land under water, the course followed in most harbors is to first determine the width of waterway in the clear between pier head lines, and the distance between pier head and bulkhead lines. The area back of the bulkhead lines so determined is then solidly filled so as to make usable land. Many acres of meadow land or salt marsh surrounding Jamaica Bay, New York, the lowlands along the waterfront of Seattle, and practically the whole harbor at Los Angeles, have been created by depositing fill secured either from the upland or by the dredging of channels.

It may be said in general that the width of waterway is not so important as its continuation as far as possible into the upland. Many narrow waterways like these, at Cleveland and Chicago, for example, carry great tonnages thus serving the industrial districts which they tap. In general city planning schemes, such waterways almost invariably should be maintained because of their great industrial value.

The Federal Government is charged with the establishing of pier head and bulkhead lines, and the army engineers are exceedingly careful in their determination of proper locations for such lines. Whenever the Government has not already made a study of the situation, it is wise to secure its action at an early date to prevent