Historical Background

According to historical accounts, the Jupiter Inlet was first shown on the explorers’ maps in 1671 and other contemporary navigation charts (U.S. Army Corps of Engineers, 1966). Originally, this was the only outlet for the Loxahatchee River, Lake Worth Creek and Jupiter Sound. Part of the discharge from St. Lucie River and the southern part of Indian River was also diverted to the ocean through Jupiter Inlet. The total flow was sufficient to maintain adequate depth through the inlet except during severe storms when the inlet closed temporarily for short periods.

This inlet has been known by several names (Dubois, 1981). First it was known as Hobe, or Jobe for a tribe of the aboriginal Jeaga Indians who lived near the inlet. On the Spanish maps, the river appeared as Jobe River, so named for these Indians. The English interpretation of Jobe was Jove, which in turn became Jupiter. On the DeBrahm map of 1770, it is given as Grenville Inlet, formerly Jupiter. Hobe or Hoe-Bay continues as the nearby Hobe Sound. All are apparently related terms. In early days, the inlet was at times several hundred yards south of the present location. The map of the Fort Jupiter Reservation, dated 1855, shows the inlet in this position.

Until the year 1922, Jupiter Inlet was a natural inlet without any man-made training structures at the inlet mouth. Under the combined effect of tidal flow through the inlet and the predominant littoral drift in the southward direction, the inlet joined the Atlantic Ocean with an orientation in the southeastern direction. Mr. J. C. Wagen, Chief Engineer of Lake Worth, Florida, approved construction drawings in the year 1922, which included the following works at Jupiter Inlet.

  1. Cutting a channel in the easterly direction across the sand barrier. The channel was to be 30 m wide at bottom with 6 ft. depth below the mean low water level. This involved removal of about 3,000 cubic yards of material.
  2. Provision of a barrier across the natural south-easterly channel, the crest elevation of the barrier being 4.5 ft. above mean low water level, in order to divert the tidal flow through the new opening.
  3. Construction of two jetties, each over 300 ft. in length, and 300 ft. apart, one on the north side and the other on the south side of the inlet. The permit for the above construction works was issued on April 20, 1922 by Mr. Lansing H. Beach, Major General and Chief Engineer, U.S. Army.

In 1922, JID built two parallel jetties about 300 ft. apart at the inlet. In 1929, the north and south jetties were extended 200 ft. and 80 ft., respectively. In 1941, a 6 ft. deep and 60 ft. wide channel was dredged close to the south jetty. In 1940, JID built an angular groin at the seaward end of the south jetty. The intended purpose was to increase current velocities and induce scouring between the jetties, where closure of the inlet had recurred. However, the inlet again closed in 1942 and remained as such until 1947.

Since JID reopened the inlet in 1947, typically biennial maintenance dredging has kept the inlet open for small-craft navigation. In 1956, a 250 ft. long concrete capped sheet pile jetty was constructed 85 ft. north of the existing north jetty. In 1966, JID working with a consulting engineering firm, initiated a 15-year improvement program intended to ultimately provide: (1) Landward extension of the existing bulkheads; (2) jetties at the seaward ends of the existing bulkheads; (3) continued periodic maintenance dredging of the inlet channel; and (4) a trestle-mounted sand-transfer plant sited north of the north jetty (U.S. Army Corps of Engineers, 1966).

A sand trap was dredged ~ 1,000 ft. west of the inlet mouth in 1966. In the late 1960’s, the jetties were modified. A “wing” on the seaward end of the south jetty was removed in 1967 in an effort to reduce shoaling within the inlet and both jetties were extended landward to prevent flanking. The present channel, about 165 ft. wide, requires regular maintenance dredging.

Chronology of Important Early Events

Year Event
1892 St. Lucie Inlet was constructed by making an artificial cut through the barrier strip, about 10 km north of Jupiter.
1896 A canal was excavated connecting Jupiter Sound and the headwaters of Lake Worth Creek with Lake Worth.
1913-1922 Inlet moved approximately 1250 ft. north to its present position.
1922 Permit was issued to Jupiter Inlet District by the Chief of Engineers, U.S. Army to dredge a channel and construct two entrance jetties 122 m apart in order to provide a stable inlet with eastward flow direction.
1922 400 ft. long jetties were constructed, 400 ft. apart and a channel was dredged to meet 6 ft. depth in the ocean.
1926 North jetty was constructed at St. Lucie Inlet. Seawall constructed on Jupiter Island.
1929 North jetty extended by 200 ft. and south jetty extended by 75 ft.
1936 100 ft. wide, 8 ft deep channel was dredged.
1940 Inlet District constructed an angular groin at the seaward end of the south jetty.
1942 Inlet closed and remained closed until 1947.
1947 Inlet was reopened by dredging.
1957 Coastal Engineering Investigation at Jupiter Island were conducted by the University of Florida in order to recommend the best methods of protecting Jupiter Island beaches.
1960 Coastal Engineering Investigation conducted by the University of Florida for recommending the alignment of bulkhead along Jupiter Island beach.
1966 Sand trap was dredged 1,000 ft. west of the inlet throat.
1967 Angular groin at the seaward end of south jetty was removed and the jetty extended by ~ 100 ft.

Recreation and Fishing

The Survey Report of 1966 (U.S. Army Corps of Engineers, 1966) mentions that the absence of a dependable, safe channel to the ocean through Jupiter Inlet restricted recreational craft from full realization of potential boating benefits. Local boats had to await favorable conditions of tides and seas or travel via the Intracoastal Waterway to St. Lucie or Lake Worth (Palm Beach) Inlets in order to cruise or fish in the ocean.

Frequently, small craft entering the ocean through Jupiter Inlet in the morning were compelled to return via Lake Worth or St. Lucie Inlets due to adverse weather or seas encountered on the return trips. Some local boatmen considered the hazard and inconvenience of using the Jupiter Inlet so great that they either kept their boats at West Palm Beach or no longer cruised or fished in the ocean. During optimum navigating conditions, normal controlling depths over the ocean bar limited recreational use to boats drawing less than 3 ft. Even with favorable conditions of sea and swell, navigation was restricted to the house of highest tide.

Accordingly, plans were drawn up to dredge a navigation channel approximately 150 ft. wide and 10 ft. deep. The channel has been maintained over the years through periodic dredging of the sand trap, the sand from which is placed downdrift of the inlet to combat beach erosion.

This protocol served the area well until the late 1980’s, when legislation was passed by the Florida Legislature requiring all agencies responsible for inlet management to develop an Inlet Management Plan.