The national park is bounded to the south by the Hawkesbury River; to the west by part of the Pacific Highway, part of the M1 Pacific Motorway, and the Peats Ridge Road; with the latter also forming the northern boundary; and to the east by the Brisbane Water, the Central Coast railway line, and urban areas.

The park is a system of reserves protecting the states significant waterways of the lower Hawkesbury River, Broken Bay and Brisbane Water.

The geology is mainly in the Hawksbury series of cross bedded quarts sandstone, conglomerates, and grey and red shales.

Other tree species that occur in this community are: blackbutt (E. pilularis), forest oak (Allocasuarina torulosa), and Sydney red gum (Angophora costata).

Vulnerable species include: thick-leaf star-hair (Astrotricha crassifolia), Camfield's stringybark (Eucalyptus camfieldii), Deane's paperbark (Melaleuca deanei), and Grevillea shiressii.

[8] The donkey orchid (Diuris bracteata) has been recorded in the area in recent times after having been listed as extinct under the commonwealth status.

[11] The vulnerable Camfield stringybarks (Eucalyptus camfieldii) range in NSW has contracted and is now only found in small numbers isolated mainly to nationals parks surrounding Sydney.

[12] The main threats to this species are: Competition from invasive non-native species and degradation of habitat from weeds, inappropriate or changed fire regimes including frequency, intensity, and timing, habitat loss and fragmentation from development, and low genetic diversity as a result of contracted population numbers.

[15] Most of the remaining population are present in Brisbane Water National Park and face similar threats to Camfield's Stringybark which are: habitat degradation, invasive weed competition, and inappropriate fire regimes.

The allocation of land in the National Park has provided and conserved valuable habitat to a range of vulnerable and endangered species as listed under the EPBC act.

A number of birds found in the park are considered rare in the Sydney bioregion due to lost habitat, these include: Collared sparrowhawk (Accipiter cirrhocephalus), Pacific baza (Aviceda subcristata), Lewin's rail (Rallus pectoralis), Buff-banded rail (Rallus philippensis), Yellow-tailed black cockatoo (Calyptorhynchus funereus), Glossy black cockatoo (Calyptorhynchus lathami), Gang-gang cockatoo (Callocephalon fimbriatum), Powerful owl (Ninox strenua), Australian masked owl (Tyto novaehollandiae), and the Red-browed treecreeper (Climacteris erythrops).

[6] The endangered swift parrot (Lathamus discolour) has been recorded in the park during their migration from Tasmania between March and October.

Foraging non breeding flocks are recorded on the Central Coast every few years and rely on healthy woodland which is species rich for their survival.

[18] Other migratory bird species known to visit the park are the white-throated needletail (Hirundapus caudacutus), The Caspian tern (Hydroprogne caspia), and the white-bellied sea-eagle (Haliaeetus leucogaster).

Other than birds, the following EPBC endangered species are known to occur in the park: giant burrowing frog (Heleioporus australiacus), green sea turtle (Chelonia mydas), The koala (Phascolarctos cinereus), which is now restricted in distribution on the Central Coast,[6] spotted-tailed quoll (Dasyurus maculatus), lLong-nosed potoroo (Potorous tridactylus), grey-headed flying fox (Pteropus poliocephalus), large-eared pied bat (Chalinolobus dwyeri), and the New Holland mouse (Pseudomys novaehollandiae).

[8] Rosenberg's goanna (Varanus rosenbergi), eastern pygmy possum (Cercartetus nanus), and the squirrel glider (Petaurus norfolcensis) are species listed as vulnerable which inhabit the park.

[19][20] The spotted tail quoll (Dasyurus maculatus) is in serious decline due to habitat loss, competition from predators, and poisoning from humans.

[21] The koala (Phascolarctos cinereus) and the squirrel glider (Petaurus norfolcensis), are arboreal marsupials broadly distributed in Eastern Australian forests and woodlands.

Arboreal marsupials rely on habitat which is influenced by the size and species of trees present, the soil nutrients, amount of rainfall, and climate.

[24] Urban development, agriculture, and infrastructure is increasingly fragmenting the required habitat for these species [23] and they are therefore more reliant on protected areas.

Park management is vital in conserving biodiversity by offering physical protection to vulnerable and endangered wildlife.

Agricultural, industrial, and domestic runoff from surrounding developments have long term harmful impacts on aquatic plant communities.

Fire suppression and management trails need to be planned so potential impacts and erosion which leads to sedimentation of creeks is minimised.