If you take energy out of the water then is has to have less energy at the other end of the pipe and that means less pressure and that means extra pumps at the other end to bring the pressure back up ... I'll bet the extra pumps will use more electricity than these turbines generate ... just another green energy scam paid for with taxpayer dollars ...

@Kaiser Derden
Exactly. That's the only way these projects work. Just use the correct "green" buzzword and it's all good. It's like they know the general public isn't going to think critically or consider basic physics. You cannot, ever, get more energy out of a system than is put into it.
If you lower the water pressure along the chain, it will require MORE energy to bring it back to a usable level by the end user.
As with anything, follow the money.

For starters, it was privately funded.
"The 200-kW Portland system was privately financed by Harbourton Alternative Energy."
Second. Our water already has plenty of pressure. I take it you don't live in Portland, or you'd not be writing such comments?

Sorry, but we don't use pumps to get our water in Portland. Read the article, it states that our system is gravity fed.
I do somewhat agree that this could be a bad idea for taking energy out of the system. Apparently there is an excess there that has been built into the system that can be drawn off without harming the overall effectiveness. Until recently the leaks between the mountains and the city were fairly epic and the subject of quite a few photo shoots. Fixing those alone over the last few years would likely keep more pressure in the system then these use.

The turbines will certainly cause a pressure drop, but being gravity fed they possibly have an over-abundance of pressure anyway; it all depends on the vertical distance between Portland and the dam (and the pipeline diameter). Anyone know this?
There are no buzzwords or pumps required here. Hydro-power is absolutely the cleanest form of energy. Essentially it uses only gravity power, nothing else.
Sure, you can't create more energy, but you CAN harness more energy out of system. Before, this energy was wasted in household taps blasting out water at high pressures. (not to mention the extra water per second).

Their website states it only uses excess pressure anyway, so maybe it won't affect end-user pressure at all.
Obviously someone studied basic physics, and thought critically.

Heh, the energy reduction problem was exactly what I was thinking, but since it's gravity fed, it'll most likely regain the energy a short while after ijt has passed the stretch of turbines, so.. Yeah.. Energy comes into the water, toppes it off, takes a bit out, and it's topped up again..

Just imagine if JUST FOR ONE DAY people actually read the entire article rather then just looking at the pictures; BEFORE posting opinions based upon unsubstantiated "facts" or personal assumptions.

So why did they use a vertical axis design rather than a turbine?
Foiled...once the energy is removed, there is a pressure drop that does not come back. Apparently they can afford some drop. It would seem more efficient at intervals along the falling pipe, rather than at one point but the proximity to electric wires might have determined that.
It would never work on a non-gravity feed system to have a net gain.

This looks like a good way to get backups in the pipe- lets put a turbine in the pipeline that can catch stuff and back the pipe up! That sounds like an excellent idea!