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Ka'elepulu Stream Breakout Session

BREAKOUT SESSION OBJECTIVE:

The objective of the breakout session was to discuss and expand, if necessary, the proposed problem statements and identify alternatives, opportunities, and issues of consideration for the planning and design of the potential demonstration project.  Here are the results that the participants came up with.  If you would like to add anything to these topics, please feel free to contact us.

PROPOSED DEMONSTRATION PROJECT LOCATION:

The proposed demonstration project is located at the mouth of Ka'elepulu Stream in Kailua Bay.  Beach sand from either side of the stream, along with terrestrial sediments, converge at the mouth of the stream and impede navigation, stagnate flow, and degrade water quality.  To the south, the beach narrows at the boat ramp and terminates at the adjacent headland (Alala Point).  North of the stream, the beach is relatively wide and advancing oceanward as evidenced by the vegetated backshore.

PROBLEM STATEMENT:Mouth of Ka'elepulu Stream

  • Sand removed from system by stream maintenance
  • Sand stockpiled on stream banks
  • Sand blown inland by tradewinds out of the system
    • May be only temporarily out of the system (small amount)
  • Sand management of Kailua Beach Park needs to consider all of Kailua Beach
  • One of the new natural beach systems (needs to be maintained)
  • Water quality - mouth/berm is a natural filter for upland water quality
    • Mangrove control issues

OPPORTUNITIES:

  • University of Hawaii did a shoreline erosion study for Kailua in 2000 and it is currently being updated
  • Keep natural beach, see what can be learned, and apply to other areas
  • Kawainui Marsh - If Corps management of the marsh is resulting in problems, then there is a funding source for the mitigation
  • Use Ka'elepulu Stream as a sand source for beach nourishment activities
  • Previous by-pass in 2000 was 10,000 - 12,000 cubic yards; No effect on Kailua Beach Park; Temporary beach a length of 500 - 600 linear feet only lasted 6 months
  • DOH is doing TMDL water quality study for the watershed
  • Dune management plan
    • Why is the beach stable, and how do we keep it stable?
  • How are Kailua and Lanikai Beaches interacting?

ISSUES:

  • How much of a buffer of sand is needed?
  • Storm events and subsequent removal of debris results in water quality issues
  • Natural versus urban river systems
    • What do they look like?
    • Natural systems are often suppose to appear "dirty"
  • Enchanted Lakes - no dredging has occurred there; There are contamination issues in the lakes
    • How does this fall into the watershed study and management of Ka'elepulu Stream?

ALTERNATIVES:

  • Develop and implement a Dune Management Plan
  • Back-pass material if we know where the material should go
    • Boat ramp?
    • Lanikai?
    • Place back into the north transport channel during the right conditions
  • Stockpile and use the material for individual erosion events, as needed
  • Restore the natural stream flows so that the channel flushes itself out
  • Restore the Kawainui Marsh natural drainage patterns
  • Develop and implement a watershed study