Council is proposing to undertake construction works to redirect stormwater flows along Illaroo Road at Lake Cathie. At present, stormwater infrastructure on Illaroo Road directs runoff onto Lighthouse Beach via two (2) stormwater outlets. These existing outlets pose risk to erosion of the beach foredune and subsequent potential undermining of Illaroo Road. It is proposed to construct new stormwater infrastructure (pit and pipe system) along Illaroo Road to direct stormwater runoff to the northern end of Illaroo Road, and discharge to Lake Cathie, therefore bypassing the existing outlets on Lighthouse Beach. This project has been identified, and further supported by the local community, as part of the Lake Cathie Coastal Zone Management Plan (CZMP) process. The CZMP identified the Stormwater realignment be included as a contingency action in the plan pending confirmation of the timing of the construction of the revetment. Therefore the redirection of the Illaroo Road stormwater outlets was identified as an action for implementation under the CZMP.
The works are intended to prevent localised erosion of the beach at each existing outlet by removing the stormwater flows from exiting directly onto the beach, thereby reducing localised scour at each outlet.
On the basis that funding of the revetment has not been confirmed the Illaroo Road Stormwater realignment was included as a contingency action in the Lake Cathie Coastal Zone Management Plan (CZMP 2016) pending confirmation of the timing of the construction of the revetment. It is proposed to undertake these works prior to construction of the wall as there will be an immediate benefit from doing so. Localised scour and erosion from the existing stormwater pipes not only reduces the natural capacity of the beach dune to replenish after storm events but it also reduces the effectiveness of the artificial dune works that Council undertakes from time to time.
Council has been successful in securing funding support from the NSW State Government under the OEH Coastal Management Program. Project costs totaling $840,000 will be equally co-funded by State Government and Council.
Commencement of the project is dependent on remediation of dumped asbestos in the foredune. Asbestos remediation in conjunction with stormwater works will proceed in order to minimise construction activity impacts to local residents. Construction works are due to commence in mid to late 2019.
This page was last updated on: 28 August 2019