2019-12-16 GC Agenda - Item 5 - Attachment 1 - Noosa Spit Shoreline Erosion Management Plan-Part 1

Noosa Spit SEMP Final Report                                                                                                                                                                                                                                                                  9
Noosa Spit Shoreline Erosion


 Imagery                                                                         Observed Changes                                        Wind Climate              Notable           Orientation      Northern Spit    Southern Spit      Dominant Flow       High Tide         High Tide
   Date                                                                        (since previous image)                                 Compared to Average          Rainfall         and Condition      Length and       Length and          Channel          Recreational      Recreational
                                                                                                                                         (since previous            (since             of Mouth         Condition        Condition                              Beach            Beach
                                                                                                                                              image)              previous                                                                                  Availability at   Availability at
                                                                                                                                                                   image)                                                                                   central Doggie      eastern
                                                                                                                                                                                                                                                                Beach         Doggie Beach

                                                   Beach. This progressively evolved into a lagoon as the continued sand supply
                                                   to the southern spit forced the channel westward away from the training wall.


July 2010                                          During the period from 2004 to 2010 there is a lack of regular imagery available   Double Island Point:     Significantly        N-S up to open    Average, wide,   Minimal   above    Multiple          Average           Limited to none
                                                   for review, so it is not possible to describe the evolution of the channels with   2009 more     N   than   higher    than       coast             submerged        HWM, average       channels
                                                   confidence.                                                                        average                  average   (and       alignment, then   shoals to west   submerged          through shoals
                                                                                                                                                               highest monthly      NE-SW                              shoals to north-
                                                   It is presumed that following the 2003 nourishment, the southern channel           Tewantin:
                                                                                                                                                               totals          on                                      west
                                                   resumed southward migration. In August 2007, a new central channel was most        More NE consistently
                                                                                                                                                               record):
                                                   likely formed in response to the heavy rainfall associated with the East Coast     from 2005 to 2009 than
                                                                                                                                                               January    2006,
                                                   Low.                                                                               average
                                                                                                                                                               August          &
                                                   The continued supply of sand to the northern spit has infilled and eventually                               September
                                                   blocked the northern channel, which has split into two. The central and southern                            2007,
                                                   channels have shared dominance. Notable recession of Noosa Woods at the                                     November 2008
                                                   upstream end of the training wall is evident.                                                               and April 2009.

                                                                                                                                                               Known    East
                                                                                                                                                               Coast Low in
                                                                                                                                                               August 2007.


November                                           Gradual consolidation of the northern spit continued, with patchy dune grass       Double Island Point:     Significantly        Multiple          Average, wide,   Minimal   above    Central,    but   Limited to none   Average
2011                                               colonisation evident.                                                              Overall less N than      higher      than     disconnected N-   submerged        HWM, minimal       multiple          (pre-groyne)
                                                                                                                                      average, but Spring      average:             S and NE-SW       shoals to west   submerged          channels
                                                   The central channel appears to be slightly more defined and the southern spit
                                                                                                                                      2011 more N than         October         &    channels                           shoals to north-   through shoals
                                                   has mostly disappeared. This is possibly in response to significant rainfall
                                                                                                                                      average                  December                                                west
                                                   inflows reinforcing the existing channel and carving a more direct exit channel
                                                                                                                                                               2010, April 2011
                                                   close to the training wall. The scour pocket at the upstream end of the Noosa      Tewantin:
                                                   Woods training wall has persisted, encouraging the retention of the southern       2011 less    NE   than
                                                   channel.                                                                           average

                                                   Localised beach nourishment equipment and small sand bulges are visible
                                                   along the eastern end of Doggie Beach. Notable beach narrowing and loss of
                                                   established vegetation continues to occur at the western end of Doggie Beach.




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