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

Noosa Spit SEMP Final Report                                                                                                                                                                                                                                                                              7
Noosa Spit Shoreline Erosion

                                                                                                        Table 2-1        Summary of Noosa River Mouth Channel Position

 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


July 1982                                          Paraphrased from Tomlinson and Chamberlain (2006):                                 Double Island Point:       Data           not   N-S                  Short      above    Average   and      Northern,     but   Limited (fronted   Limited (fronted
                                                                                                                                      SE   dominant     over     available                                 HWM,         long   wide    above      multiple            by shoals)         by shoals)
                                                   Southern spit and ebb-tidal delta enlarged due to Main Beach nourishment.
                                                                                                                                      preceding years                                                      submerged           HWM,        long   channels
                                                   Channel in a similar position and shape to previously observed but the entrance
                                                                                                                                                                                                           shoals to south     submerged          through shoals,
                                                   has migrated further north due to growth of southern spit and ebb-tidal delta.     Tewantin:
                                                                                                                                                                                                                               shoals to north    shoals adjacent
                                                   Northern spit eroded as a result of this migration. Northern channel is the        Equal NE & SE, less S
                                                                                                                                                                                                                                                  to         Doggie
                                                   dominant flow path but the southern channel may be re-opening.                     than average
                                                                                                                                                                                                                                                  Beach




May 1986                                           Paraphrased from Tomlinson and Chamberlain (2006):                                 Double Island Point:       Data           not   Shore-parallel       Average,            Short     above    Central,      but   None (fronted      None (fronted
                                                                                                                                      SE dominates, more E       available            west           of    narrow,             HWM,        long   multiple            by shoals)         by shoals)
                                                   Several interceding years of photography were considered. The southern
                                                                                                                                      Autumn 1983, more N                             coastline,   then    submerged           submerged          channels
                                                   channel reopened. A period of vacillation between opening and closing of the
                                                                                                                                      Summer 1984 than                                N-S                  shoals to south     shoals to north-   through shoals,
                                                   southern channel occurred while sand was being supplied into the channel from
                                                                                                                                      average                                                                                  west               shoals adjacent
                                                   Noosa Woods (ocean) beach. While open the channel cut back slightly into
                                                                                                                                                                                                                                                  to       Doggie
                                                   Noosa Woods. At the same time, the northern spit grew and the entrance             Tewantin:
                                                                                                                                                                                                                                                  Beach
                                                   migrated southward. Eventually the southern channel increased in dominance         Equal NE & SE, more E
                                                   as the major flow path. During this period, the orientation of the entrance        in 1983, less S than
                                                   changed from north to east and back to north.                                      average




December                                           Paraphrased from Tomlinson and Chamberlain (2006):                                 Double Island Point:       Data           not   Shore-parallel       Average,            Minimal   above    Southern       –    None               Wide      (infilled
1990                                                                                                                                  SE dominates, less SE      available            west            of   narrow,             HWM, average       Hard up against                        shoals)
                                                   Several interceding years of photography were considered. The northern
                                                                                                                                      in 1987, less N to NE in                        coastline,   then    submerged           submerged          Doggie Beach
                                                   channel breached the northern spit and became the dominant flow path while
                                                                                                                                      Spring 1989 & 1990                              NE-SW                shoals to south     shoals to north-
                                                   the material that previously formed the southern spit blocked the southern flow
                                                                                                                                      than average                                                                             west
                                                   path. The southern channel progressively re-established, resulting in both
                                                   channels operating simultaneously, sharing a single exit with two well developed   Tewantin:
                                                   spits. The northern channel was progressively infilling.                           Equal NE & SE, less N
                                                                                                                                      in 1990 than average




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