New Zealand & John – Pt 2

G’day M8s,

John again from New Zealand. Here are a few more thing of erosional interest, call it “erosion control around the world”

During the big Hobson Highway Deviation Project field tour I learned they were trying an innovative “green wall” for a highway bridge. The six-inch thick reinforced concrete wall had holes it it. Behind the holes were Delta-lok geobags. The bags were filled with growth medium. Native plants “plugs” were then inserted into the bags. Another experiment they had going was to try it with an additional geotextile between the bags and the concrete. What do you think??

I got to hook up with Robert Coulson again. Robert had taken all of my classes at the IECA Conferences (and I think anything else IECA had to offer) and to see him again was so gratifying. Robert has brought all that knowledge and technical expertise to New Zealand. He has several hydroseeders, mulch/compost blowers, straw blowers AND he is growing and propagating a shrub willow that is very useful for Bioengineering projects – which he has done many!

Note Salix sp. are not native to NZ and most see them a s a nuisance. However, digging a little deeper I discovered that the “BAD” willow here are a tree willow growing along streambanks. These willow trees are referred to as “Crack Willow”, not a drug thing but they “crack and break off and then cause flooding”. Soooo Robert is using an shrub willow for brushlayering, and quite successfully. He is building ‘live walls’ for road repair using compost socks (Filtrexx) and brushlayering. These projects and all his others have been so successful and cost-effective that Robert’s company is getting quite a good reputation in this island nation. Maybe we can post some of these projects in the future?

Also, check out some of the cool stuff the North Shore City Council has going on.

Robert and I got invited to visit some sites with some of the North Shore City Council planners. This was really the high point of my trip. These guys had attended my full day class – Environmentally-Sensitive Streambank Stabilization. The attendees got a free manual on CD, the NCHRP Report 544 on Environmentally-Sensitive Channel and Bank Protection Measures. Nothing like going out in the field and discussing solutions to real world problems. It was raining also during the trip so it was a real rain slicker/ mud boots trip.

Typical urban problems – water quality and stream incision. However, the North Shore Council has a really progressive stream restoration and park development project just about ready to go. This project will (over 800 meters of stream work) get implemented BEFORE full urbanization in the area is experienced. This is a great example of good planning and environmental sensitivity.Check out this regional stormwater detention that the North Shore City Council did. This project “has it all going on” – stabilized pool/riffle stream, floating gabion islands, and habitat galore. Good Job!!Hey it is raining so hard and cold. I rented a camper van. Last night, driving down to Palmerston North the winds were gusting 60 mph and the rain was sheeting horizontal, whoa! Check out all the flooding rivers!! I’m guessing more than bank-full discharge, or above mean annual high water or 1 in 5 yr storms!!! new plymouth, my favorite so far.

I am GOING to Fiji, no kidding
More from there, Ciao John


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