BACKGROUND

In 2010, we were enlisted by our hotel developer client to protect and enhance their beach’s amenity at Jangwani on the East Coast of Tanzania. At the time, our client’s hotel boundary was under severe threat due to erosion.

PROBLEM

The dominant feature of the coastline and the hotel’s beach frontage was a rocky shelf, which extended some 300m from the shoreline and was completely exposed at low tides. The sandy beach in front of the hotel was undernourished and eroding.

We conducted extensive survey of the site and prepared detailed design of a number of options to protect and enhance the beach’s amenity. Key factors driving design were retaining the visual aesthetics and usability of the beach for hotel guests, together with achieving a practical construction methodology that could easily be managed by a local contractor using largely manual labor. Upon approval of the final design, construction works were carried out in 2011.

SOLUTION

Balancing the need for a user-friendly construction methodology, together with achieving a visually appealing beach, Ecocoast designed a highly practical and cost-effective structure to protect the hotel and improve the beach simultaneously. The structure consisted of a terminal seawall partially buried under nourished beach along the property boundary using 5-tonne sand-filled geosynthetic container bags.

The seawall was designed to provide erosion protection in severe events and delineate the sandy beach and landscaped areas, as well as provide user-friendly stepped access down to the beach. The design also included a mixed geosynthetic container and gabion groyne/breakwater.

EFFECTIVENESS

Almost 7 years on, and with zero maintenance during this period, the protection works continue to perform as designed. The hotel’s beach has seen no further erosion since completion of the works in 2011, even during storm season where the coastline is subjected to high waves and wind. The hotel’s protected sandy beach is in stark contrast to the adjacent property’s beaches, which are rocky and subject to severe erosion.