Table of Land use in Manly Lagoon Catchment
| Type of Land Use | Area (km2) | Area (%) |
| Residential - low density | 6.62 | 37 |
| - low-medium density | 2.31 | 13 |
| 8.93 | 50 | |
| Industrial | 1.22 | 7 |
| Business | 0.24 | 1 |
| Open Spaces - Recreation | 2.67 | 20.3 |
| Bushland | 3.7 | 14.7 |
| Education & Technical Facilities | 11.7 | 7 |
| TOTAL | 17.9 | 100 |
The open space generally lies adjacent to the lagoon and its tributaries. Approximately half of the open space is linked to Manly Dam, which ceased operating as a water supply source in 1942 and is now a recreational resource.
Source: Manly Lagoon Estuary Management Study 1995