Residents call for more detail about floodplain works
Peninsula Residents' Association has called on Central Coast Council to provide more detail of action dates and costs for its floodplain management works.
The association said the details were needed to facilitate budgeting and the initiation of project planning.
The comments were made as part of the association's submission about the council's draft Woy Woy Peninsula Floodplain Risk Management Study and Plan.
"Trading off drainage design standards for a fully-operational drainage network sounds good in concept," the submission stated.
"However, the study gives no data or projections of the competing scenarios either in budgetary terms or in effect in flooding events.
"It pays no attention to maintenance requirements or of the consequence of neglecting them.
"It provides no works or maintenance priorities, but seems to accept a status quo of an ad hoc and piecemeal approach to drainage works on the Peninsula.
"Teatree Creek (the main drain) is ranked by the Council as a high priority creek and its function as a drainage channel is clearly critical to flooding in most of the north-west portion of the Peninsula.
"Despite this, there is no integrated management plan or works program that covers its length from Ryans Rd to Correa Bay."
The association's submission described the basis of the draft plan as "tenuous".
"The study acknowledges lack of data across a range of factors, including drain flows, flood levels, recent rainfall figures, rainfall rate (eg by quarter hour), drain sizes, drain invert levels, and drain condition.
"And it still relies on just one calibration event 35 years ago, recorded 25 years after the event with just 20 locations.
"With a changing climate, it is all the more important that all the contributing factors are continually monitored and more than one calibration event is available to attenuate the model."
The submission also questioned a reliance on planning provisions in the Council's Development Control Plan to implement mitigation measures.
To be effective, Council planning staff would need to adopt practices to ensure these provisions were not undermined, it said.
"Standards including setbacks, density, open space and impervious surfaces should be strictly and immediately enforced in all development approvals.
"The current practice of allowing variations, simply on the assertion without substantiation that the associated objectives are met, is already having a cumulative impact on flood risk for future occupants and whole suburbs.
"The Development Control Plan is a fragile instrument.
"It is clear that Council planning staff through their own decisions can undermine the strength and integrity of a Development Control Plan.
"It is the association's view that Council planning staff have both a professional and an ethical obligation not take action or make decisions that would have this effect.
"However, the in-house practice standards seem to have slipped in recent years and it may be time to review them for their effectiveness for implementing recommendations of this draft Floodplain Plan."
The submission urged the council to adopt more recent projections of sea level rise by 2100, and to pay more attention to road access.
"Emergency response facilities need to be secured and provided to ensure the protection of the community in an emergency," the submission stated.
"While this is acknowledged in the study, no specific recommendations are made.
"The recommendations for reviews of emergency management arrangements lack the necessary urgency, given the level of risk and challenging topography.
"Work on this should start immediately, with priority actions identified and funded for each of the next five years in Council's Strategic and Operational Plans."
SOURCE:
Submission, 15 Feb 2023
Jennifer Wilder, PRA