The City of Onkaparinga is South Australia's largest metropolitan council and one of the states fastest growing areas. The region includes 31km of coastline and covers 518 square kilometres.
From Sellicks beach in the south to Christies beach in the north, the coastline consists of stable cliffs and sandy embayed beaches. Sediment supply to sandy beaches is projected to decline and therefore shoreline recession is expected with sea-level rise. A storm surge hazard zone has been designated at the mouth of the Onkaparinga river, and a number of potential drift hazard zones (vegetated sand dunes; as opposed to actual drift zones which includes erosive sand dunes) are designated along the coast. Sellicks Beach is a designated flood hazard zone.
The distribution of advantage is uneven within the City of Onkaparinga. Over 40% of suburbs fall within high levels of disadvantage (≤30th percentile) and 15% have higher levels of advantage (≥80th percentile) compared to the national average. Other indicators of economic vulnerability are consistent with the Australian average; although there is a lower proportion of residents living in rental housing. Onkaparinga has a greater proportion of single parent families, fewer foreign-born residents, and less diversity in language spoken than the Australian average.
Socio-economic characteristics, 2016
| 2016 | Onkaparinga LGA | Australian Average |
| Economic | ||
| Rental stress | 10% | 11.50% |
| Mortgage stress | 8.20% | 7.20% |
| Low income households | 22.20% | 23.70% |
| High income households | 7.60% | 11.20% |
| Rental housing | 24% | 30.90% |
| Unemployment | 7.70% | 6.90% |
| Economic diversity Index | 0.93% | 1 |
| Population | ||
| Total population | 166,766 | NA |
| <14 years | 18.70% | 18.70% |
| >65 years | 17.30% | 15.80% |
| Median age | 40 | 37 |
| Single parent families | 18.40% | 15.80% |
| Lone person households | 24.80% | 24.40% |
| Aboriginal or Torres Straight Islander | 1.60% | 2.80% |
| Birthplace not Australia | 26.90% | 33% |
| Language other than english at home | 6.70% | 22.20% |
| Community | ||
| Volunteering rates | 19.30% | 19% |
| Health (Type 2 Diabetes) | 6% | 5% |
| Residents receiving government social service payments | 74% | 68% (South Australia) |