Utilizing existing watershed creek

Question
There is a watershed creek that runs right behind my Minnesota home (some parking lot and agricultural runoff, but mostly from the 16k acre wildlife sanctuary about 5 miles upstream). I have a small 5k square foot lot and a busy highway 100 yards away. I have been contemplating pumping the creek water up about a 10 foot rise, perhaps 25 feet away, and building a small pond area with a rock/creek return spillway back to the creek. Basically a pondliner-filled gutter dug in the dirt and filled with rocks. I'm looking for some ambient sound to drown out the road noise, but am wondering about the logistics of the pump size, silt filtration and possible algae growth. I thought perhaps even a timed flow cycle for mornings and evenings, leaving the pond area to rest during the day. I've searched the web, but everything I find is self contained. Any suggestions or warnings about doing something like this? PS: I'm not really looking for supporting fish or plants, although I'm sure I'll try a few, and if nature allows it, great, it would go well with all the birds I feed and the little gardening that I'm allowed with such a little spit of land ;)

Answer
Glen,

In order for a pond to balance and attain maximum clarity, it has to be a closed system so that the plants can remove all the excess nutrients that the bacteria convert to nitrates.  We call it the nitrogen cycle.  It is impossible to get a pond to balance if you constantly add new water and new nutrients to it.  Consequently, it will never clear.  In addition, the constant circulation of nutrient rich water down your stream/waterfall will grow great volumes of string algae.  This is why all the information you find requires a closed system.

Now, having said all that, you CAN do what you are proposing.  If you are OK with a "natural" setup which includes all the "natural" algae, then there will be no problem.  If you are OK with a green pond then there will be no problems.  The plants and fish really prefer it that way.  It is us who need the clear pond.  Shutting down the waterfall a couple days a week to let it dry will help keep the string algae in check.

Usually when I explain all this to a customer, they opt to go ahead and create a closed system so it will stay cleaner and clearer.

As far as pump size, I would recommend a good quality waterfall pump.  A 3000 gph will give you a nice waterfall about 2' - 3' wide.  A 6000 gph will supply a waterfall 5' - 6' wide.  In either case, use a 2" diameter pipe so you will get full flow.

Hope this helps,

John