Stream Reconstruction Lessons Learnt
Water Symposium 27 Nov 2014
Mark Lewis Boffa Miskell
DESIGN
CONSTRUCTION
LA ROSA
Stream Reconstruction
Stream Dynamics Stream Profiles Channel Formation Bank Stabilisation Design through Construction
STREAM DYNAMICS
1. Bankfull discharge is a range of flows that form channel, floodplains, and banks. (Ward, D'Ambrosio, & Witter, 2008)
2. Generally associated with a ‘medium’ storm with a recurrence of 6 mth to 2 yr. (McCuen, 2004; Rosgen, 2004; Clar, Barfield, & O'Connor, 2004; MacRae & Rowney, 1992; MacRae, 1991)
3. Unpredictable in urban environments, this can as likely be a 1/3 year recurrence. (Ward, D'Ambrosio, & Witter, 2008; Shields Jr., Copeland, Klingeman, Doyle, & Simon, 2003)
4. The events that actually shape this bankfull channel through shaping in‐channel features occurs more often perhaps several or many times per year (Gippel, 2001; Ward, D'Ambrosio, & Witter, 2008; Alliance of Rouge Communities, 2012).
5. To maintain stability, a river needs to transmit the incoming sediment load without net erosion or deposition (Hey, 2006; Shields Jr., Copeland, Klingeman, Doyle, & Simon, 2003)
Flowrate 1 2 3 4 5 6 7 8 9 10 11 12
No.Events Events/Yr 445 304 172 90 46 35 9 4 3 1 1 0
37.1 25.3 14.3 7.5 3.8 2.9 0.8 0.3 0.3 0.1 0.1 0.0
ARI* 0.03 0.04 0.07 0.13 0.26 0.34 1.33 3.00 4.00 12.00 12.00 #DIV/0!
CONSTRUCTION
LA ROSA
: Education
(Objective 6)
“Everyone I have spoken with were truly impressed with what has been achieved at the reserve, and I’m really pleased we now have an open-air classroom” (quote from the Principal of the local primary school)
Acknowledgements Auckland Council Stormwater Transpower NZ Fletchers Construction Heb Landscapes EDC Limited Tonkin and Taylor Beca Aecom NZ