Figure 16. Settlement at Avalon, New Jersey, Beachsaver site (Bruno et al., 1996b).

700

Stauble and Tabar

Figure 16. Settlement at Avalon, New Jersey, Beachsaver site (Bruno et al., 1996b).

(HERRINGTON et al., 1997). The seaward extent of the profiles

three groins from scour by the strong tidal eddies (HERRING-

TON et al., 1997).

was at the Beachsaver Reef. A total station with prism rod

The reef structure was placed in more shallow water than

was used in the collection of the beach profiles out to the reef

the Avalon reef between 2.1 and 2.4 m ( 7 and 8 ft)

crest and a fathometer was used for the offshore bathymetry.

MLW, with a crest elevation of between 0.15 and 0.61 m

A pre-installation profile data set was collected in May 1994

(0.5 and 2.0 ft) MLW (BRUNO et al., 1996a). This shallow

and a post-installation survey was collected in September

crest elevation close to MLW makes this installation different

1994 (Table 4). Additional beach profile surveys were collect-

from the others in this report. A geotextile fabric was also

ed in November 1994, February, May, July, September, De-

placed under the reef units on this installation for scour pro-

cember 1995 and April and August 1996 (HERRINGTON et al.,

tection, but the thickness was doubled as compared with the

1997). Offshore bathymetry surveys were collected in May,

Avalon project. A 1.3 m (4.3 ft) wide polyethylene geomat-

September and November 1996, May, July, September and

tress filled with 6.1 to 10.2 cm (2.4 to 4 inch) stone was placed

December 1995.

along both the landward and seaward side of the base to mit-

Settlement measurements were made by measuring the

igate for scour based on the experience with the Avalon mon-

tops of the reef units with the total station and prism. Set-

itoring. To further stabilize the reef steel H-piles were driven

tlement surveys were made in September and November

to a maximum depth of 3.05 m (10 ft) below the bed at all

1994, February, May, July and September 1995, and April

end and transition units (BRUNO et al., 1996a).

and August 1996. Two InterOcean System S4 electromagnet-

ic current meters were installed inshore and offshore of the

Monitoring Program

reef to obtain wave and current data for one day on 25 July

1995 (HERRINGTON et al., 1997). The inshore meter was 3 m

Project monitoring included the creation of a 457 m (1500

(9.84 ft) landward of the reef in a water depth of 2 m (6.56

ft) long baseline covering the two pocket beaches where the

ft) MLW. The offshore meter was placed 5 m (16.4 ft) seaward

Beachsaver Reef was constructed and a control area to the

of the structure in a water depth of 4 m (13.12 ft) MLW. The

west in the next groin compartment. A total of 12 profile lines

meters recorded for 18 minutes every hour for six hours from

were established, with 5 in the first groin compartment, 5 in

09:00 to 14:00 at a depth of 1m (3.28 ft) above the bed. A dye

the second compartment and two in the third. Two of the

study was performed on 27 September 1994 to examine any

lines were removed after November 1994 giving an along-

reef influence on water circulation in the vicinity of the reef.

shore spacing of around 45.7 m (150 ft) between profiles

Journal of Coastal Research, Vol. 19, No. 3, 2003