Port Fairy Seawall in Place Hazard Lines

Brief description

The Port Fairy Local Coastal Hazard Assessment (LCHA) provides information on the extent of coastal hazards and their physical impacts for the Port Fairy coastal environment.

This data considers setback of the present day shoreline due to coastal erosion if existing seawall (where present) remains in place. The four key components of coastal setback that are incorporated into this hazard line are:
- S1, allowance for short term storm erosion (storm demand 100 year ARI);
- S2, allowance for dune stability (zone of reduced foundation capacity);
- S3, allowance for ongoing underlying recession; and,
- S4, allowance for recession due to future sea level rise.

The total design setback (S) for three planning horizons comprises:
- Present day: S = S1 + S2;
- 2050: S = S1 + S2 + S3(2050) + S4(2050);
- 2080: S = S1 + S2 + S3(2080) + S4(2080); and
- 2100: S = S1 + S2 + S3(2100) + S4(2100).

Sea level rise projections utilised for the planning horizons were 0.4 m for 2050, 0.8 m for 2080 and 1.2 m for 2100 respectively. Where appropriate, the +6 m AHD contour was used as a reference as it was considered to represent the coastal alignment reasonably. The crest of the rock revetment was used as the reference contour on the southern half of East Beach. For low-lying dune systems the +2 m AHD contour was used.

Details of the assumptions made in the derivation of this information can be found in project reports on the Our Coast website: http://www.ourcoast.org.au/cb_pages/resources.php.
Users of this information should read these project reports to understand the limitations of the data.