Pond Boss Forums INTRO Questions & Observations Anyone ever filtered a small natural stream

I'm thinking about building a man made bio filter for a constant tiny stream I have going through my property. Like the ones you see at Home Depot or at your local pond store...but just on a bigger scale. Has anyone ever filtered there stream? Im trying to prevent silt going into my pond.

There are a number of threads here on settling basins or marsh filtering etc. Also several guys are doing so now. If they don't chime in I will locate the threads.

Yeah I know about marsh filtering and using an upper pond to catch the silt before it goes into your main pond. Ive never heard of anyone hooking up a home depot style (plastic balls and styerfoam filter in a box) off the shelf filter. Im just wondering how often they have to clean it?

Face72-

We install large watergardens (30' x 50') and we still have to clean the foam filters and catch basket inside the skimmer at least once a week. You can see the flow greatly reduced each week if you go any longer.

Obviously in your situation, if a rain event happened, it would collect more sediment and would have to be cleaned more frequently. Otherwise you could cause a flooding problem up-stream.

Do you have aquatic plants in the pond itself? If so, they can be adding to the silting of the pond. We have found that Pickerlweed especially produces a great deal of muck and silt.

An aeration system can be retrofitted to inject alum into the pond. The alum will attract the suspended solids and sink them to the bottom. This will keep the pond crystal clear. We have never done that on a "flow through" system and honestly, I don't think it would achieve the same results. The meter would have to self adjust to meet the flow rate into the pond.

Just my brainstorming. Good luck.

Thanks for the info. I figured in big rain storms it would require more cleaning.

carey, what do you mean when you say "We have found that Pickerlweed especially produces a great deal of muck and silt."?

it produces muck or catches it?

you are negative on pickerlweed?

i dont think it provides alot of food, but alot of cover.
thankyou

also, do you have picture of watergarden?

Depending on the amount of filtration expected, I sort of question the feasability filtering stream water especially during spates (floods). Everything will depend on the size of the stream and the ground cover of the watershed. Flood waters of a stream can be pretty forceful (raging) and amazingly strong in terms of current and erosive force. This erosion could cause lots of problems at the head waters of the settling pond. The settling pond would need quite an extensive amount or lateral expanse of plant stems to slow the water flow enough to get settling of the finer clay particles. However, any suspended solids (SS) that you can get out of the stream flow before the SS are deposited into the lower pond then that would be a least some benefit.

Note - if your design causes a slow down of the flow of the stream with the use of a large bio or physical filter also consider if slowing the flow of the stream will cause water to back up somewhere upstream that could cause other new problems on someone else's property.

There are issues and concerns whenever you try to filter a stream for upstream flooding, However there are ways to do this and slow down the flow such that you remove most of the silt prior to getting tot he pond. The best method I have seen used ( and I did this myself ) is to take a straight creek and have it switch back and forth in a zig zag motion this will slow the flow of the creek. To ensure that the creek does not cause a large back up up stream the creek must be widened enough to hand the heavy flow conditions during a large rain fall. This is very important to make sure it can handle it appropriatly. If you dont cut it wide enough it will blow over the zig zag and wash everything out and actually cause more silt or dirt to get into the pond.

Once you have the zig zag done at the right width you can add rocks/boulders in the creek to slow the flow and act as a drop out point for the silt. You can also add in the appropriate vegitation to help slow the flow. The trick with vegitation is to pick something that will not get into the pond and over run the pond.

Thus over all make creek into zig zag and widen and add rock and vegitation. I hope this helps!!

face72,

If the stream is real small, consider widening it to 6-8'. If you widen it and shallow it up, grass will grow in and around the bed. This will slow down the flow and allow more sedimentation and filtration by the grass.

I intend to choke 15a of catchment down to 1 filtered inlet. I plan to build a large limestone filter bed to keep trash out and fish in after a rain. Even now, my runoff is very clear from filtering through grass in very shallow ditches.

I've built a small concrete dam to hold a bale of hay. The water flows through the hay and is filtered before it enters a 4" drain tile which feeds my pond. The tile exits the stream at a 90 degree angle to feed my pond which is about 150 feet away from the stream. (small stream, approx 15-20 gpm average flow) The concrete dam has another exit for the water if the bale of hay clogs up and I don't change it or if it rains hard and the flow is too much for the bale to filter. The second exit for the water is about 2/3 of the way up the bale of hay.When the water reaches the second pipe height it just flows down the hill and only what trickles through the hay makes it to my pond. This gives me filtered water 90% of the time and hard rains are diverted. I usually have to change (shovel out) the mud clogged bale and replace it every 4 to 6 weeks on average. The water is much less muddy and the muddy hay composts into great topsoil.

PaPond - consider taking the hay bale apart and stuffing the "straw" into a large mesh, large bag similar to those that they wrap a Christmas tree in at the Xmas tree farms. Or you could make your own bag or large cylinder from plastic snow fence or similar large pore material. I think the bag of hay would act as a better filtration device plus it should be easier to manage and replace.

Good idea Bill, the space I put the hay in is the exact size of a bale but I'm sure I can wrap the bale with plastic snow fence and pull it out whole. In fact since there are trees on both sides of the filter I can put up a beam and hoist the wet bale out with a come along. My back feels better already!

Cliffbrook,

No, its not that I don't like pickerlweed, in fact, it looks great in mono-cultures especially when it is in front of the white blooms produced by arrowhead.

I was just giving information on our findings around 95% of pickerlweed that we encounter.

Here are a couple of pond photos per your request: