Modelling Combined Outfalls

[Gearoid O Sullivan]

Hi,

I am modelling a sewage network and WwTP arrangement in Infoworks ICM. Initially I modelled 3 outfalls at the WwTP (high level emergency overflow at inlet pump station, storm pumps at inlet pump station and an overflow from a storm tank). This worked fine with no flooding in the network.

I was then instructed to combine the 3 outfalls into one as per the image attached. When I do this I get flooding throughout the network. There is also negative flow in the emergency overflow pipeline. When I put a flap valve on the end of this pipe it cleared the network of flooding.

Can someone explain to me what is happening here?

Thanks

Kind Regards,
Gearoid

[Martin Spiers]

It looks like your "outfall" isn't an outfall,flow will be controlled by the link downstream.

Hi,

I am modelling a sewage network and WwTP arrangement in Infoworks ICM. Initially I modelled 3 outfalls at the WwTP (high level emergency overflow at inlet pump station, storm pumps at inlet pump station and an overflow from a storm tank). This worked fine with no flooding in the network.

I was then instructed to combine the 3 outfalls into one as per the image attached. When I do this I get flooding throughout the network. There is also negative flow in the emergency overflow pipeline. When I put a flap valve on the end of this pipe it cleared the network of flooding.

Can someone explain to me what is happening here?

Thanks

Kind Regards,
Gearoid