Past Corrective Measures 



During the period 1938-19^7 over 5 million cubic yards of sand were 

 pumped from the harbor entrance area to the beaches north of the break- 

 waters. The material was dredged by the hopper dredge "ELesbok" (Figure 3) 

 and pumped from that dredge, moored alongside the north pier, through a 

 U2-inch discharge line to a point on the beach about 5,000 feet north of 

 the north pier. The results of this 9-year replenishment operation were 

 the restoration of about 3U areas of beach area between the north pier 

 and West Street and about U0 additional acres of accretion in areas north 

 of the revetted Lower Marine Parade to Umgeni River. The beach fronting 

 the revetted area of the Marine Parade did not widen significantly, 

 although accretion was occurring in areas on either side. Beach areas 

 south of the pipeline discharge location continued to erode. 



In 1950 a fixed bypassing plant was placed in operation. This plant 

 consisted of a 16-inch pump with crane-supported suction mounted on a 

 steel pier south of the south breakwater (see Figure h). The pump was 

 connected by flexible rubber coupling to a 16-inch discharge line which 

 ran under the harbor entrance. When uncoupled from the discharge line 

 the crane and pump suction could be moved along the pier to a protected 

 location as required. This plant could dredge to 20 feet below low water 

 and the suction pipe could swing through 180 degrees with a radius of 

 36 feet. During the period 1950-195U this plant bypassed approximately 

 200,000 cubic yards of sand per year across the harbor entrance, discharg- 

 ing 5,000 feet north of the north pier until 1953, when the discharge 

 point was shifted to a location just clear of the base of the north pier, 

 (See Figure $.) Replenishment at that rate apparently maintained stability 

 of the shore line north of the harbor entrance to Umgeni River. However, 

 damage still occurred during the more severe storms in the Lower Marine 

 Parade area just north of West Street. 



To create a wider beach in this latter area two groins were con- 

 structed in 1953 in addition to a storm drain (Somtseu) that acted 

 as a groin to the north of this area. (See Figure 9.) The most southerly 

 groin (number l) widened .the beach on its south side a maximum of 135 feet 

 during the first six months after its construction in April 1953, but 

 erosion caused by subsequent storms in September and October reduced the 

 beach widening to about 85 feet. 



Photographs of the revetted Lower Marine Parade area and the groins 

 are shown in Figures 6 to 9. 



Concluding Remarks 



The City Council of Durban, on the basis that the city*s operation 

 of the bypassing plant materially assisted in maintenance of the harbor, 

 requested assistance from the South African Railways and Harbours 

 Administration in operation of the bypassing plant. In lieu of such 

 assistance an agreement was reached whereby the Railways and Harbours 



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