UFC 4-150-06
12 December 2001
Table 5-1 Principal Factors in Harbor Siting
Factor
Considerations
External Access
1. Vessel access to harbor site contains adequate depths and clearance for safe
navigability.
2. Land access to harbor site is or can be reasonably developed to provide
required land transportation linkage.
Size and Depth
1. Protected water depth and space adequate to accommodate intended vessel
traffic in the following areas: (a) entrance and turning basins, (b) mooring
areas, and (c) berthing areas.
2. Land areas of sufficient size and elevation to accommodate support needs free
from flooding or inundation.
3. Potential for future enlargement or change in harbor use.
Physical and
1. Sheltering from winds and ocean waves; natural sheltering features such as
Topographic
headlands, offshore reefs, and islands will reduce both artificial sheltering
requirements (breakwaters) and costs.
2. Limited fetch. The protected water area shall not contain segments of
sufficient fetch to act as a generating area for waves that would cause
difficulties within the harbor.
3. Bottom. Heavy, stiff, or overconsolidated clays furnish the best holding ground
for anchors. Sands will provide acceptable holding ground. Sites should be
avoided where the bottom consists of extremely hard clays, rocks, or very soft
clays. If this is not possible, costly provisions (such as mooring islands) must
be made to secure ships. Similarly, the costs of breakwaters, piers, and shore
side structures will also depend upon the underlying soil conditions. Location of
extensive structural systems in areas of deep, soft clays should be avoided.
4. Dredging. Avoid locations involving dredging of large quantities of rock or other
hard bottoms.
5. Shoreline relief. Land adjacent to shoreline should gradually slope away from
beach. Avoid locations with pronounced topographic relief (cliffs) adjacent to
shoreline.
6. Upland drainage. Preferably, the upland area should be naturally well drained.
Evaluate occurrence of health hazards due to local conditions.
Hydrographic and
1. Variations in water level. The range between water level extremes due to
Hydrological
cumulative effects of astronomical and storm tides as well as flood flows in
river-affected harbors should be minimized as far as practicable.
2. Currents. Current velocity should be minimum and, except for localized areas
and/or special considerations, should not exceed 4 knots.
3. Fouling rate. Desirable factor is a low fouling rate and relative freedom from
marine borers, hydroids, and other biofouling organisms, which can be drawn
into the cooling systems of ships.
4. Water circulation. Water basins should have sufficient natural circulation.
5. Sedimentation. The effect of the harbor site on natural regimes of coastal and
riverine sediment transport and supply must be thoroughly evaluated. It is
desirable not to interfere with the natural regime of sediment movements. The
effects of harbor development on the sediment system may require
maintenance dredging and/or shore-stabilization needs that must be
considered as part of the overall development effort.
Meteorological
1. Storm. Avoid locations subject to the direct effects of pronounced, severe, and
frequent storms.
2. Fog. Consider local variation in fog intensity and avoid the more severe sites
where practicable.
3. Ice. Avoid locations that might be ice-locked for several months a year.
Other
1. Availability of construction material. In particular, rock for breakwater and jetty
construction.
2. Fresh water availability. In particular, water for potable water supply.
5-2
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