Design is based on CIRIA C (the SUDS manual) & BRE Digest edition (Note: BRE issued an updated version in , the spreadsheet is. Established in , CIRIA is a highly regarded, industry-responsive, not for profit . She was the principal author of the previous SuDS Manual (CIRIA C). within the SuDS Manual (CIRIA C, ) and a related Susdrain Factsheet on maintenance4. (Wilson and Davies, ). 1
|Published (Last):||4 January 2013|
|PDF File Size:||5.27 Mb|
|ePub File Size:||20.78 Mb|
|Price:||Free* [*Free Regsitration Required]|
CIRIA – The SUDS Manual – Engineering Nature’s Way
Southwest Environmental Limited can undertake surface water drainage strategies using ciriw of the above methods. Where they differ is that whilst BRE uses field data to derive an infiltration rate and works out a soak away volume based on this rate, CIRIA C is based more on limiting flows cirua site, without considering where they go. In order to carry out a BRE Soak-Away Test you will need to excavate some trial holes, and fill then with water and watch how quickly in soaks away.
In clay soils this can take a long time, so you may need to watch the hole for a few hours, in a gravel soils it could be all over in 10 minutes. The hole size needs to be “representative” of the soak c69 you intend to use.
Depth is the most important factor to consider in most cases. Once you have your infiltration data, the calculations are carried out in accordance with BRE ciriz Various factors are considered such as region southeast drier than southwestan allowance for climate change, size of test hole, and finally your recorded observations.
These are then used to establish whether you input area say m2 will create say liters of water during a 1: You will then get a results showing the size of the trench you need to dig, in order to provide enough infiltrations drainage.
With CIRIA C as with BRE the site area is input in to cirria calculations, but in this instance you can select areas of differing permeability, for example roofs and or grass areas. The more grass proportionately the smaller you attenuation feature will be. The calculations will now provide you with an attenuation volume.
Which will provide storage of water so as to smooth the impact of a a heavy rainfall event on the surround surface water system whether that be natural or manmade.
Around 4 tests can be carried out simultaneously over the course of a day on site. A water supply is not required as we can normally arrange this even at short notice. BRE soak-away testing cannot be carried out on contaminated sites.
PUB C SUDS manual, CIRIA – Publication Index | NBS
This is because the EA do not accept soak-away drainage on cirua site, and carrying out the tests themselves may wash contaminate off site on in to aquifers. On very steep sites it can be difficult to get water to the holes, and it may need to be pumped from the nearest available flat area. Each test typically uses around liters of water, it must citia added to the hole quickly so as to simulate a natural rapid rainfall event.
Please note that soak-away for foul drainage is carried out according to a different method. A smaller pit is typically used, which is hand dug, sometimes in the base of a larger machine dug pit.