AGENDA - Sunshine Coast Council

Strategy and Planning Committee Agenda 16 February 2011
TIDAL PRISM
Cardno have completed a Tidal Prism Review which is primarily based on existing studies
which were undertaken at the time the original Pelican Waters canal system was proposed.
The northern end of the Pumicestone Passage is a dynamic system with the location of sand
banks within the passage and the location of the Caloundra Bar itself moving over time. This
natural variation in the Pumicestone Passage has historically resulted in changes within the
tidal prism within the Pumicestone Passage of 25%. In comparison the increase in tidal prim
associated with both the existing and proposed waterways of Pelican Waters range from
3.6% to 5.6%.
The combined effect of the existing and proposed waterways on tidal velocities at the
Caloundra Bar would be 0.7% for the ebb tide and 0.55% for the flood tide. In reality the
increase in tidal velocity will result in a slight increase in the cross sectional area of the
channel and the increase in tidal velocity at Caloundra Bar would be negligible.
The increase in tidal prism and tidal velocity at the entrance of Lamerough Canal will be of
greater significance than at the Caloundra Bar. In addition, within the existing Lamerough
Canal the channel is enforced so there can be no increase in cross sectional area and
increased velocities will be realised. The increase in tidal prism will however not result in any
scour impacts within the existing Lamerough Canal.
In summary the effects on the Pumicestone Passage due to the increase in tidal prism
resulting from the construction of the additional waterways would be almost negligible and
would be masked by naturally occurring variations in the tidal dynamics of the Pumice
Passage.
CARRYING CAPACITY FOR WATER CRAFT
Given the application seeks to include an 80 Wet Berth marina and a 200 Berth Boat
Stacker, it is reasonable to suggest that as a result of the proposed land uses, the number of
private boats utilising and recreating in the waters of Pumicestone Passage will increase.
Vessel registration data obtained from Maritime Safety Queensland shows that at 30 April
2010, 8,132 vessels were registered in areas with convenient boating access to Pumicestone
Passage. The natural increase of vessel registration is approximately 4.2% per annum. It is
submitted by the applicant that it is estimated that the proposed development may increase
the amount of vessel registrations with convenient access to Pumicestone Passage by
between 5.5% and 7%. It is difficult to measure the actual increase of motor boat usage on
the Pumicestone Passage.
Council adopted the Waterways and Coastal Management Strategy that details major
deliverables for natural waterways, of which the Pumicestone Passage Catchment is
identified, include the development of Catchment and Estuary Management Plans and the
establishment of marine zones.
It is proposed to commence the development of a catchment and estuary management plan
for the Pumicestone Passage in early 2011. This plan is intended to be a tool that will allow
catchment and passage management issues to be identified and prioritised and suitable
management actions (including costs and timelines) developed for priority issues. The plans
will consider:
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