Orange growth in a natural spring fed water fearture

Question
I don't know if you are the one to ask or can advise me where to seek a solution.  My problem is that I have a natural spring in my back yard in Portland, Or, which I made into a water feature of stream and a series of ponds (with liners) as it goes to a larger stream.  For years it was a beautiful looking small mountain creek/stream with clear water.  For the past 6 years or so, it has become infested year round with a rapidly growing matter, that I presume is some form of algae.  The water itself looks clear, but this matter seems to grow, resulting in my having to "flush" it downstream every several days.  If longer than a week it builds above the water level and develops a hardening, cake like materal.  It doesn't seem to smell, but has surely taken the esthetic beauty out of this natural water feature.  Barley packets don't work.  Since the water if freely flowing, I would assume something that is added to the water at it's source would be required.  If you have any ideas or can stear me to someone with expertise in this area, I would be very grateful.

Answer
Hi Greg,

Depending on where you are, your spring could be receiving a lot of nitrogen from regular lawn and agricultural chemical fertilizer.
This is a serious problem.
Hi nitrogen levels in the water favors the growth of algae. Too much algae will block the sunlight, and that will kill the ones that are growing at lower depths.
As they decay, they will generate methane, which is toxic to fish an coral reefs.
(See data on the rapid disappearance of shellfish on the estuary of the Mississippi River. See also about the Chesapeake Bay.)
You could use algaecide, but that would only add more unwanted chemicals to the environment.
The best thing to do would be to make an assessment of the possible source (s) and try to change it.
This is a matter of educating people.
If we don't learn, we will surely pay a price for it.

Can you send me pictures of the area?


You can send them to:

Carlo@organiclandscaping.com