The Parangarahu Lakes Block was added to the East Harbour Regional Park in 2004 after the cessation of a grazing lease to a local farmer. This block of land includes Lake Kohangapiripiri and Lake Kohangatira, as well as the historic Pencarrow Lighthouse. The steep hillsides and pasture are slowly regenerating with manuka and kanuka starting to overtake the gorse. The dunes and ridges of the raised gravel beach support several threatened plant species such as leafless muehlenbeckia and sea holly. The lakes now support a rich succession of wetland vegetation, including oioi (jointed wire rush) and glasswort closer to the sea, and raupo, toetoe, flax and giant umbrella sedge further inland.
The Parangarahu Lakes are also a haven for birdlife in the Wellington Region with over 50 species found there. These include regionally rare species such as dabchick, tomtit, rifleman, whitehead, kakariki, falcon, banded dotterel and grey duck. The surrounding land is also home to a wide range of other native fauna of regional importance such as the green gecko, copper skink, giant kokupu, the land snail (Wainuia urnula) and velvet worm (Peripatus).
The area was to be allowed to regenerate naturally but to speed up the process MIRO proposed the establishment of a nursery to grow eco-sourced trees to attract birds and facilitate the spread of native seed into areas of gorse. The first revegetation plot was established in 2007 and plots continue to be added annually.