Bung:

 

MikeAqua:

 

Clay is hopeless, especially on slopes but on flatish land it can be improved over time - with the right treatment and planting.

 

 

Clay can give you nasty surprises on slopes. At our Wellington house there was a break in the ceramic stormwater pipe. The surrounding Clay absorbed water until it took on a porridge consistency and flowed downhill. That sort of thing is repeated regularly throughout the region. If it is a council owned pipe it is always determined that "it was the slope failure that damaged the pipe" not the other way around.

 

Puts hand up. What’s a good water sucking, bank holding plant for a slope. Stupid here was sold 5 exotic fir trees 25 years ago that have grown shorter and not more than 165cm tall. Outside bonsais with thick trunks, barren branches burnt to a crisp by the wind. I leave them in hoping the roots have spread to hold the bank. Want to plant others in between that will survive the extremes. 

https://www.rnz.co.nz/news/community/593240/homes-gutted-and-businesses-closed-as-wellingtonians-count-the-cost-of-floods

What I find difficult to grasp is some of the flooded homes were situated in places never before deemed a flood risk. You can bet our insurances go up a heap everywhere in the city not just in the flood prone areas. I know a couple of people who haven’t had any insurance for many years and are prepared to take the risk. The way house prices have risen and insurance getting so expensive a lot more people will be forced to take this path.  

gzt: Probably a good thing they did not grow tall. Maybe that's what they are designed to do?

No they were meant to grow about 10 meters. Great wind break I thought at the time. They aren’t even half a meter wide and very ugly but they stay as can also be used as posts to tie wind cloth to protect new plantings. May as well be useful for something. Natives would have flourished.

Maybe, you  could end up with flax and coprosma as your natives if it's that windy. Your library may have a copy of a NZ book Gardens in the wind by Jacob De Ruiter. 

MikeAqua:

 

It's actually been fun geeking out on this part of the design. 

 

100%

good job on the oversized gutter and downpipe. its an increase in cost but keeping the overflows away from the house keeps the house safe. design it so it overflows at the detention tank and then you can control where the overflow goes and follows your overland path.

i've done similar, detention tank for half the roof and the overflow goes over safe overland route. otherwise gutter overflows just end up going to the road and adding to the flooded storm drain (after its messed with the garage on its way pass). i still have the garage to do, it has the issue of undersized storm pipe under the concrete, and no good overland path. 

tweake:

 

 

 

developers don't want the added cost and in theory if the storm water design is ok, then they should not need to.

 

 

 

It isn't just for storms though, but also for water to reduce load on water supplies. Developments create additional load on supply and it doesn't appear that councils in many areas have been collecting enough money from developers to increase infrastructure.  New houses are usually also required to have soak pits anyway as that is usually part of the consent.

mattwnz:

 

It isn't just for storms though, but also for water to reduce load on water supplies. Developments create additional load on supply and it doesn't appear that councils in many areas have been collecting enough money from developers to increase infrastructure.  New houses are usually also required to have soak pits anyway as that is usually part of the consent.

 

that starts to get tricky. town/city water systems are there to insure good clean water supply, and that its cheaper than doing your own. we have seen what happens when that fails. its not great having the cost of your own system as well as the cost of the public system. plus many fail to maintain it unless they actually want it. i've spent most of my life on tank water so i'm all for people having their own tanks for their own use if they want to pay for and maintain it. neighbours have one for the garden, you can also have one to run the toilet.  but they have to be maintained if they are for drinking etc.

soakage pits only exist in aeras that have free draining soils, so they don't have to build storm drains. i've never seen one because i'm in clay country.

developers contributions is a curly topic. funding infrastructure costs was recently in the media. the no1 problem with developers funding infrastructure is the cost gets put onto the housing market and that inflates housing prices, and home owners in turn pay, roughly speaking, about double that cost (because of mortgage interest rates). so basically council pushes infrastructure costs onto a minority of home owners who take out a loan to pay for it and end up paying double. plus cost tends to get pushed down the housing ladder so fhbers tend to wear it. council funding needs to change and developers contributions need to end.

tweake:

 

that starts to get tricky. town/city water systems are there to insure good clean water supply, and that its cheaper than doing your own. we have seen what happens when that fails. its not great having the cost of your own system as well as the cost of the public system. plus many fail to maintain it unless they actually want it. i've spent most of my life on tank water so i'm all for people having their own tanks for their own use if they want to pay for and maintain it. neighbours have one for the garden, you can also have one to run the toilet.  but they have to be maintained if they are for drinking etc.

 

 

 

Were they are required in my area in certain subdivisions, it is solely used for garden and WC usage which don't require any treatment.  So new houses are plumbed for it to be used just for those applications. So that still takes a large load of the reticulated system, as many peoples water usage is in the garden.

tweake:

 

developers contributions is a curly topic. funding infrastructure costs was recently in the media. the no1 problem with developers funding infrastructure is the cost gets put onto the housing market and that inflates housing prices, and home owners in turn pay, roughly speaking, about double that cost (because of mortgage interest rates). so basically council pushes infrastructure costs onto a minority of home owners who take out a loan to pay for it and end up paying double. plus cost tends to get pushed down the housing ladder so fhbers tend to wear it. council funding needs to change and developers contributions need to end.

 

Having the cost of new infrastructure fall on new developments makes sense to me... happy to be convinced otherwise, but I'm not sure how it should be the responsibility of existing residents to pay for the profit margins of developers out in the wop wops. 

tweake:

 

100%

 

good job on the oversized gutter and downpipe. its an increase in cost but keeping the overflows away from the house keeps the house safe. design it so it overflows at the detention tank and then you can control where the overflow goes and follows your overland path.

 

i've done similar, detention tank for half the roof and the overflow goes over safe overland route. otherwise gutter overflows just end up going to the road and adding to the flooded storm drain (after its messed with the garage on its way pass). i still have the garage to do, it has the issue of undersized storm pipe under the concrete, and no good overland path. 

 

It's not that much extra in the scheme of building (and having engineered!) an unconventional house design.  That said, there are lot of things that aren't that much extra individually, but they sure add up!

We're fortunate to have ponds.  We'll have multiple storage tanks for roof water for domestic, irrigation, washdown and firefighting.  Overflow goes to one of the ponds.   That pond can overflow to the other pond.