NOTES ON BISCAYNE BAY. 189 



REPORT* ON A PRELIMINARY EXAMINATION OF BISCAYNE BAY 



By Thomas H. Handbuuy, 

 Major, Corps of Engineers, U. S. Army. 



I have the honor to submit the following report upon a preliminary examination 

 made by me of the entrance to Biscayue Bay, Florida, authorized by the river and 

 harbor act of August 17, 1894. and directed by your letter, August 20, 1894: 



Biscayue Bay is located upon tlie east coast of Florida and near its southern 

 extremity. It is about 36 miles in length, with an average width of 6 miles, and has 

 an approximate area of 216 square miles. Over fully one-half of this area there is a 

 low-water depth of 6 feet and less; over the remaining half the average is not above 

 10 feet. There are occasional holes where the water is 13 feet, and iu the cuts which 

 connect ifc with the ocean depths as high as 16 and 18 feet are to be found. The 

 mean rise and fall of the tide is 1 foot. 



The west shore of the bay is coral rock, As^hich rises in places to a height of from 

 6 to 10 feet above the water level. This rock extends back under the Everglades, 

 the eastern edge of which is about 6 miles from this shore of the bay. Several small 

 streams that take their rise in the Everglades empty iuto the bay. The most con- 

 siderable of these is tlie Miami Elver, at the mouth of which old Fort Dallas was 

 located. About 4 miles from the mouth of this river there is a rapid a quarter of a 

 mile iu length, ou which the fall is about 4 feet. 



This seems to be the edge of the rim which holds the water of the Everglades at 

 its present level. By excavating through this the level of water would undoubtedly 

 be lowered and much valuable land reclaimed. The east side of the bay is limited 

 throughout its entire length by coral reefs that have risen from the ocean bed. The 

 greater portion of these are above high water, have some soil upon them, and are 

 covered with a thick growth of mangrove, saw palmetto, and other semitropical 

 vegetation. These are commonly designated "keys." The balauce that is not to 

 this height is covered with sand, bare at low water. Through this reef there are 

 several openings or "cuts," by means of which communication is had between the 

 bay and the ocean. Outside of this- line of keys, at a distance of about 3 miles, aud 

 running nearly parallel to it, there is a second line of detached coral rocks that are 

 only just awash at high water. There are also numerous rocks of the same character 

 lying between the two reefs. In these waters lie what is known as Hawk Channel, 

 an inside passage permitting a draft of about 12 feet from Cape Florida around to 

 Key West. This is taken advantage of by light-draft vessels coasting along these 



Communication is had with Biscayue Bay by these boats through the passages 

 just under Cap*^ Florida — Bear Cut and Norris Cut. These may be considered as the 

 "entrances to Biscayne Bay" contemplated by the act of Congress, and have been 

 the subject of this preliminary examination. 



Norris Cut is the most northerly of these entrances, and is the first to separate the 

 keys from the mainland. It is about one-fourth of amile iu width, and has upon its bar 

 at low water about 4 feet. I was told by reliable persons well acquainted with these 

 waters that there is a reef under this bar with about 2 feet of sand upon it. This 



* Dated February 18, 1895, and addressed to Chief of Engineers, U. S. Army. 



