Below is the motion I have co-written with Councillor Vissel for the Lane Cove Council meeting on the 19th April 2021:

Executive Summary

As building density increases next to existing urban bushland, at night-time the light emanating from buildings and landscape create light ‘spills’ into the neighbouring bushland. This artificially turns a dark environment at night into an illuminated environment.

The objective of this motion is for Council to conduct further research to identify if there are existing examples of planning instruments and guidelines that can considered to limit the impact of light ‘spill’ on urban bushland.

Background

As our built environment and population has increased extensively in Lane Cove, we have experienced more development immediately adjacent to urban bushland. Examples of high-density residential development next to urban bushland in the last decade include the Mowbray Precinct and Waterview Drive in Lane Cove West. 

Development proposals are underway for the construction of projects adjacent to urban bushland at 266 Longueville Road (Australian Unity), 276 Longueville Rd to 18 Northwood Road (Pathways), Greenwich Hospital (Hammondcare) and the Lane Cove Sport and Recreation Precinct (Lane Cove Council) on the site of the Lane Cove Golf Club building and car park. Council is also reviewing the lighting in several sports fields.

As building density increases next to existing urban bushland, at night-time the light emanating from buildings and landscape create light ‘spills’ into the neighbouring bushland. This artificially turns a dark environment at night into an illuminated environment.

Lane Cove’s history of protecting bushland

The Lane Cove area has an abundance of wildlife thanks to the wonderful urban bushland it sustains.  The recently completed Wildlife Survey publication commissioned by Lane Cove Council, available on our website, shows the extent of the species which includes birds, microbats, frogs, turtles, skinks, geckos, dragons, echidnas, swamp wallabies, sugar glider, possums and flying foxes to name some and include nine (9) threatened species.

This abundance of wildlife is no doubt due to the dedication of Lane Cove Council and its staff together with the bushcare, backyard habitat and bush friend volunteers in regenerating our bushland to the standard it is today.

Discussion

Impacts of light ‘spill’ on urban bushland

In January 2020, the Australian Government released its National Light Pollution Guidelines for Wildlife.  Their opening sentence states:

“Natural darkness has a conservation value in the same way that clean water, air and soil has intrinsic value. Artificial light at night is increasing globally by about two per cent per year. Animals perceive light differently from humans and artificial light can disrupt critical behaviour and cause physiological changes in wildlife.”

Three quotes from the research paper Light pollution at the urban forest edge negatively impacts insectivorous bats by Haddock et al Biological Conservation Vol. 236 August 2019 (listed below)  state:

1)   “Connectivity and quality of vegetation in cities, including urban forests, can promote urban biodiversity. However the impact of anthropogenic pressures at the forest-matrix edge, particularly artificial light at night (ALAN), on connectivity has received little attention”;

2)   “Artificial light sources on the edges of urban forest have diverse effects on bats and insects, and should be considered an anthropogenic edge effect that can reduce available habitat and decrease connectivity for light-sensitive species”; and

3)   “Only relatively recently has ALAN been widely discussed as a global threat to biodiversity.”

Light Spill impacts have also been noted in Council’s Bushland Fauna Survey (June 2020) Chapter 9, at page 236.  We therefore believe that this issue of light ‘spill’ on urban bushland needs to be addressed as a matter of urgency.

Current planning instruments

There is a chapter dedicated to the protection of bushland in Council’s Development Control Plan (DCP), Section H, which endeavours to preserve and protect our bushland when development applications adjacent to bushland are considered. 

The existing Australian Standard AS4282 is limited to light obtrusion as a benchmark for people living in an urban environment. This considers what people are expected to tolerate as a result of an adjacent external lighting installation.  Council’s current planning instruments do not consider the impact of light ‘spill’ on urban bushland and its impact on fauna.

(Sources:-Light pollution at the urban forest edge negatively impacts insectivorous bats (Abstract)  (Joanna K Haddock, Caragh G.Threlfall, BradleyLaw, Dieter F.Hochuli) Biological Conservation Vol. 236 August 2019; Manuscript: Light pollution at the urban forest edge and its impact on insectivorous (JK Haddock, CG Threlfall, B Law, DF Hochuli); National Light Pollution Guidelines for Wildlife Including Marine Turtles, Seabirds and Migratory Shorebirds (Department of the Environment and Energy, 2020); Bushland Fauna Surveys Lane Cove Council (June 2020))

Conclusion

As building density increases next to existing urban bushland, at night-time the light emanating from buildings and landscape create light ‘spills’ into the neighbouring bushland. This artificially turns a dark environment at night into an illuminated environment.

This motion seeks Council support for the conduct of further research to identify if there are existing examples of planning instruments and guidelines that can considered to limit the impact of light ‘spill’ on urban bushland.