3-3 



2 2 



km of this area representing the inner harbor and 14.1 km the outer 



harbor (areas determined from mean low water (MLW) datum contour on 

 NOAA-NOS Chart No. 218). Mean depths below MLW are 3.5 m for the total 

 harbor with 2.7 m and 3.7 m for the inner and outer harbors, respect- 

 ively. Since the mean tidal range for New Haven Harbor is approximately 



7 3 

 1.9 m (NOAA-NOS, 1977), the tidal prism is approximately 5.3 x 10 m . 



This prism represents a conservative estimate of the mean volume of 



water that must flood into and ebb out of the harbor during a complete 



tidal cycle. The entrance to the harbor is formed by a dredged channel, 



the depth of which decreases from approximately 10.4 m at the breakwater 



entrance to 4.9 m at the Ferry Street Bridge in the Quinnipiac River 



(Figure 1-1) . 



Hydrology of the New Haven Harbor Drainage Basin 



2 

 The Quxnnxpiac, Mill and West Rivers drain a total of 624 km 



2 

 (241 mi ) of south central Connecticut, with the Quinnipiac contributing 



about 80% of the total flow. Normal precipitation and runoff data from 



U.S. Geological Survey records (USGS, 1959 to 1976) show little monthly 



variation over a well-doc\imented annual cycle (Long Island Sound Regional 



* 

 Study, 1963) . This annual cycle of estimated total monthly runoff for 



1967 to 1977 shows peak values in March (mean of 24.2 m /sec), a gradual 



3 

 decrease through the spring and early summer to a low of 7.1 m /sec in 



August, and then a gradual increase through the fall and winter culmina- 

 ting with the March peak (Figure 3-1) . This annual cycle plays a major 

 role in the patterns of harbor circulation. 



* . 2 



Assuming uniform rainfall over the entire 624 km area, runoff data 



from the gauged portions of the drainage basin were used to esti- 

 mate runoff from the ungauged portions and compute an approximate 

 monthly total. 



