Onsite detention system

@TML

Tom,

Without stamped plans from certified storm water engineer....it is just guessing game.

As @bob shovel Said, huge cost difference between above and in ground and half of dozen other variables.

Dual fail safe pump with switchboard could cost $10k + plus install/config cost.

Comapre to

$1500 water tank.

 

Good in theory. But in many cases the council engineering dept specifies the preferred retention method. Ie. They regulalry say no to above ground storage greater than 2500Lt.

Civil engineers are paid well to design and compute systems and know the councils preferred method.

 

@Be Developer. Thanks . At my site it doesnt need a pump as it has a easement connection at the rear.

Yes, agree that the OSD costs are depended on the stormwater / hydraulic engineer coming back with a design/plan then work out the materials from there.

However, iam asking a ball part figure for big ticket items specifically for:-

1. Above water tank 3000L - generally $1000

2. Below ground OSD - generally $/m2

Yes i know there are other smaller items and labor costs.

Council actually have under their website a storm water manual guidance which helps with calculation OSD (i.e Roof area and all hard surfaces)

What iam after is a general estimation to allow sufficient cost in my budget.

 

@TML its not that easy. the tank size, depth, site, pipework to tank and to outlet, head pressure to choose pump.
to many variables.
from what others have said its 10-60k, so ifyour after number you could go for the middle $35k or you could use worst case $60k

 

It cost me $8k for pit and pipe plus the cost of 2 2000ltr tanks in build. For 2 X units.

 

Thanks Cactus. How big was your land and you must have a minimal slope?

Did you mean 2x units as in two townhouses? and how big were they?

How big was your pit? was it underground made of concrete? also called a detention tank?

 

@Rockstar does all of your roof area then have to be diverted to the tanks?