Pond newbie - Buying home with 3000 gallon pond

mokittyAugust 25, 2012


I am completely new to the world of ponds. We are purchasing a home on several acres in the town of Duvall, WA (about an hour from Seattle) that has a pond in the backyard. We estimate the size of the pond to be about 3000 gallons. We currently can't tell if this pond is naturally occurring or if the previous owners built it. The house sits on a hill and the pond is at a low spot in the property. We cannot see any liner of sorts, but there are rocks around the edge of it that seem to have been placed there by someone. There is also a pipe that empties into it, but we do not know where this comes from (or if it is even functional). There is quite a bit of life in and around this pond. There are lots of plants growing in it and many frogs coming and going from it, some of which are quite large. One end of the pond appears to once have had a bridge over it, but it is now collapsed and overgrown. We have wondered if the pond does or used to connect to a stream on that side, but currently it is too overgrown to tell. The water is pretty clear, too, although I cannot see all the way to the bottom. I have not had a chance to look closely enough to see if there are any fish in the pond. There are lots of water bugs of different sorts around it, though.

So as a complete newbie to ponds, where do I begin? I would like to maintain and encourage the lovely ecosystem that already seems to be around the pond, as well as cut back the overgrowth and enhance it's aesthetic aspects. I don't know if I need to do anything to encourage the water to be "cleaner" or add nutrients. How do I go about trimming/removing plants in the pond (and should I) as well as those around the edges? Can I safely add creatures like fish or turtles to the pond in the future? It is in quite a rural area, so I would assume deer and other animals probably visit the pond sometimes.

Does anyone know of a good book or resource for working with ponds, particularly in the PNW climate?

I will add a couple more photos shortly.

Thank you for reporting this comment. Undo

Another photo of the pond:

    Bookmark   August 25, 2012 at 6:22PM
Thank you for reporting this comment. Undo
sleeplessinftwayne(z4-5 IND)

Since it is in a low area and there is water draining into it from a pipe, it is probably either natural or designed to control and localize run-off from higher levels. It may or may not have a liner, but my guess is it is lined with clay if at all.

In any case it seems to be a holding pond. Without it you would likely have a marsh.

To control the inevitable mosquitoes and black flies you can use BTi aka Bacillis Thuringiensis israelensis. It is commonly sold under the name Mosquito Dunks. It would be totally safe for all the other wildlife that lives in and around your lovely pond.

The biggest reason for it not to be an ornamental pond is that it is placed low ground. Ornamental ponds are usually placed on higher ground to avoid collecting run-off which can carry chemicals into the water. Yours is the exact opposite.

    Bookmark   August 25, 2012 at 7:18PM
Thank you for reporting this comment. Undo

Thanks for the response, sleepless.

Can I still manicure it some if it is not intended to be ornamental? I.e., I won't alter the basic structure of the pond, but can I still add or remove plants, trim/prune things to make them more visually appealing? I can tell the plants on the end of the pond with the collapsed bridge were once cut back quite a bit due to the fact that there was once a bridge there.

Is there anything I should or shouldn't do in light of the fact that it is probably either natural or designed to control run off?

    Bookmark   August 25, 2012 at 7:35PM
Thank you for reporting this comment. Undo
sleeplessinftwayne(z4-5 IND)

Went back to read your post again so... more info.

A good source for help with a holding pond would be the DNR. How much help you get depends on who works at your local office. Not everyone is an expert at everything. The local Extention Service may help as well.

The pipe is probably the end of drainage tile/field. If you are lucky they put it in properly and not too long ago. With a bit of research you may be able to find out who installed it.

I would wait a year to see how the pond is functioning before doing any major work or adding critters. That will give you an idea if there are any problems such as water levels changing rapidly, noxious weeds, tile field needing repaired, dredging required or what ever else may pop up. You may even have fish in it that were brought in as eggs by birds. A first step would be to have the water tested.

You definitely have critters coming to the pond.

    Bookmark   August 25, 2012 at 7:41PM
Thank you for reporting this comment. Undo

Thanks again, sleepless! That's really helpful information.

Just one last questions, since I really am a newb... what's the DNR?

    Bookmark   August 25, 2012 at 8:05PM
Thank you for reporting this comment. Undo

I've been doing this for a few years and don't know what DNR is either. Perhaps Department of Natural Resources, but have never used that name. It sure isn't Do Not Resusitate which IS a good accronym.

Most here don't have natural ponds. It sure looks like that's what you must have. You can certainly go after the land with a mower and loppers on the big bushes to see whats going on. It might be wise to google 'clay sealed pond' before indiscriminately yanking plants from the pond bottom.

    Bookmark   August 25, 2012 at 8:42PM
Thank you for reporting this comment. Undo
sleeplessinftwayne(z4-5 IND)

LOL, chas. You are correct, the initials do stand for Dept. of Natural Resources.

As can be expected there are a lot of those alphabet agencies out there that may or may not be helpful. Which one has helpful info. in your area varies in the extreme. Some are identical to other agencies that have totally different objectives. Then there are private companies that want to sell you something.

Mokitty, there is no reason in the world why a holding pond, retention pond, dew pond cannot be ornamental. From what I see in the photos, someone has tried to do that in the past and has recently let it go. Recently being totally subjective.

The grasses around the pond can be cut back, the old bridge removed or replaced, wild shrubs and other plants identified and volunteer saplings removed. That should keep you busy for a while.

Cutting back the grasses will help control the number of migratory ducks that use the pond.I wouldn't mention the ducks to anyone but the Extention service and would be cautious even there. They might prevent you from doing anything that might change the current function of the pond including cutting the grass. The Environmental Protection Agency is well known for that. Avoid them if possible.

Here are some sites that look like they can give you decent info on the purpose of your pond.


Call the DNR and the Extension service and specifically ask "Do you have any material related to small retention ponds or dewponds and wildlife habitat?"

This is one of those projects that may or may not require lots of planning and/or physical intervention. For now, look for traces of a previous pathway to the pond and improve that. Starting at the bridge may go faster. Observe what the weather does to the water level. Keep track of water levels for as long as you can, months are better than weeks and compare them with rainfall. See what happens to the pond and the surrounding area during and after a heavy/light rain. Locate and clear any over/outflow. Identify grasses and other plants. They may have been chosen for specific purposes such as erosion control, wildlife cover, food source, etc. Tall grasses may prevent debris from overwhelming the pond. Search for electric hookups. Do they even exist? Is there a bad odor like sewage that would indicate dredging for organic matter is needed and the pond is deficient in oxygen. Float something on the surface to see if there is any sort of water movement. You might find that overflow where your float ends up. Check the soil on the outside of the pond and on the inside of the pond to see if it is the same. Are there lots of rocks on the sides of the pond? How deep is the mulm/debris on the bottom? Did the former owners leave any pond equipment behind?

Get the water tested or get a testing kit and do it yourself. No strips. They just don't give good readings.

There are people out there who can do the hard work of cleaning out the pond for a hefty price. Before you hire them, know enough about what the pond does that it will be you in charge.

Ask questions. There are enough posters here to answer most questions or who will send you where you can get the right answers.

I hope this has not overwhelmed you.

    Bookmark   August 26, 2012 at 4:14PM
Thank you for reporting this comment. Undo

Sleepless, thank you again for all the info. Really helpful.

We went out to the house this weekend (still waiting to close so we don't live there yet), and I took another look at the pond. It hasn't rained here in a while, so it was lower than last time. We found out during the inspection that during wetter times of the year the pond does indeed connect to a stream that runs under the collapsed bridge. I also saw a small fish in the water! It was about 3" to 3.5" in length. My husband thought it was a large tadpole, but I'm pretty sure it was a fish. We also saw several very large bullfrogs there, as well as some enormous green and blue dragonflies.

    Bookmark   September 4, 2012 at 1:37PM
Thank you for reporting this comment. Undo

Here is a photo of the pond from this weekend. You can see a little more of the vegatation living in the water itself, but I couldn't get a decent photo of the little fish.

    Bookmark   September 4, 2012 at 6:45PM
Thank you for reporting this comment. Undo
sleeplessinftwayne(z4-5 IND)

Hey there. I wrote such a nice long response and then before I could send it the cat jumped up...not even my bad language could recover it so I will try again.

Good job finding out new info. Observation is an excellent learning tool along with asking questions. When you next have a chance, see if there is a dam on the other side of that bridge. If there is you can hold the water in the pond longer in a dry season, you can make the pond deeper if the sides of that little dell are steep enough and if there is a weir, you can let water out with little effort.

The DNR or the Co-operative Extension Service at your local land grant college or University may be able to ID the water plants or may have some publications on the subject. I am familiar with Indiana, Wisconsin and Ohio info but I am at a loss with what Washington's might have. Another resource would be the Public Library. I will look up some titles and authors that might be helpful tomorrow. Just remember there is no real hurry. That pond has been there for a while.

I'm jealous.

    Bookmark   September 10, 2012 at 5:22AM
Thank you for reporting this comment. Undo

Sleepless, I'm really excited for this pond. I would be jealous of me, too.

My husbeast had a conference call with the seller about the property to ask questions. Sadly I had to work, so I didn't get to bombard him with all my questions about the pond, but this is what husbeast told me he said:

The pond is naturally occuring, but it got "a lot of help from him". He said when they moved in years ago, it was more of a swamp and he dug it deeper and connected it to a stream that runs under the collapsed bridge, and created a drainage system where rainwater from up higher runs into the pond via the pipe we saw. He said that one year his young son dumped lake bass in the pond, and then dumped gold fish in the pond to feed the bass. The bass died, but the gold fish were thriving and some grew 6 to 8" long... until a Heron came down and ate all the gold fish. So I'm assuming the fish I saw was left over from that. He said every year in the spring a beaver shows up and tries to build a damn where the stream connects to the pond. He said he and his wife really enjoyed watching the beaver, but you have to stop him before he gets to far with his dam.

Anyways, we are hoping we can move soon... this one's a short sale, so nothing happens quickly with this kind of house purchase.

    Bookmark   September 10, 2012 at 9:21PM
Thank you for reporting this comment. Undo
sleeplessinftwayne(z4-5 IND)

That beaver could be a problem. They don't have weirs. Left to build they can make the entire area of low ground into a swamp unless you do a lot of digging to enlarge the pond area. I love bog gardens but... Advice on eliminating or re-homing the beaver can be obtained through the DNR. Ask the seller if they had someone do it for them and take names. At least the DNR can tell you what the laws and regulations might be. That will keep you out of difficulties. There are different rules in different places. I would start saving up for some good binoculars and heavy leather gauntlets.

We live in town and it always amazes me just how much wildlife is around us. The neighbors don't always believe me if I caution them about leaving their pets out at night. Last week DH said he saw a large fox walking nearby. I have insomnia and often sit by the pond at night and watch the critters come to drink and play. The only available water I know of is more than a mile away in ditches and several retention ponds. Those require critters to go across busy highways. I'm sure the drought has been hard on them. I just don't see the larger animals like the deer we saw in Wisconsin although I have seen them on the IUPurdue Campus a mile away. The poor things are getting displaced because of the new buildings there. You will be sure to see some deer if only at a distance.

If you get lots and lots of ducks and geese you may need to reduce the population. You aren't allowed to kill or hurt them but they can be controlled. The thing that is a problem is illnesses from their droppings in and around the water. Lots of rain will reduce the problem most of the time. If you are not on their flight path they will not be a problem.

The drainage system is great to have. That hillside up to the evergreens looks like it would shed a lot of water. It would be nice to know how extensive it is and what materials they used. It looks like the sellers did a lot of improving but I wonder why they did not fix the bridge. Was it set in concrete? It might have rotted out if the supports were too close to the water. I'm not sure why it is so close to the stream. If you decide to replace it you may want to change its location to a higher spot.

One thing that might help you is a county soil survey map. They are the responsibility of the Department of Agriculture and I am pretty sure those have been completed. You may be able to find it on the internet for free but not all counties have done that. It shows the general topography of the area and the basic geology which is helpful if you plan improvements or have a well. We wound up building on top of a granite shelf and had to use dynamite to finish the well. Details are nice even if you don't plan lots of improvements.

I hope you don't run into difficulties with the closing. There are a couple of houses through the years we looked at that didn't go through for one reason or another and it was very frustrating. For the most part it was due to the seller not wanting to pay for necessary structural repairs. That is always a killer problem.

    Bookmark   September 11, 2012 at 8:04PM
Thank you for reporting this comment. Undo

We're supposed to close in 1 to 2 weeks now. It's been an extremely long journey finding this house and waiting for the shortsale to close. But we're in the last stretch now.

Thanks for all the advise so far, Gardenweb!

    Bookmark   October 6, 2012 at 2:30PM
Thank you for reporting this comment. Undo
sleeplessinftwayne(z4-5 IND)

I've got my fingers crossed for you.

    Bookmark   October 10, 2012 at 4:09PM
Thank you for reporting this comment. Undo
botann(z8 SEof Seattle)

I have several unlined ponds on ten acres and live a few miles south of you in Maple Valley. I'm familiar with your area. Perhaps I can be of assistance.
I'm hoping the deal went through for you.

    Bookmark   November 18, 2012 at 10:29AM
Thank you for reporting this comment. Undo

Hi Mike,

It did go through! We have been living in the home for a few weeks now. I know where Maple Valley is, heh.

We have had torrential rains the past 48 hours, and when I woke up this morning I discovered the pond is already a full foot deeper than it was last week (and it was already much bigger last week than it was in August). Fortunately, it's well down hill of our house.

I have discovered another, very large pond on the property that has not been manicured the way the first pond was. The first pond does indeed feed into a stream that loops around our property a bit and then goes into the neighbor's property.

I wish our weather was better this time of year! It's very cold, wet, and sloppy right now, so I cant yet do much in terms of dealing with the overgrowth.

    Bookmark   November 20, 2012 at 1:41AM
Sign Up to comment
More Discussions
Pond Heat
What is the best method of heating water to 70 degrees...
Dressing and coping a formal pond
Is there any general advice for how to dress the interior...
ysrgrathe PA 6b
Dividing lotus this weekend
I have a Carolina Queen lotus that has to be divided...
Making Mechanical Prefilter for submersible pump
My medium sized pond is currently using the Savio watermaster...
Frogs found dead in my pond
It's been a while, and I can't find anything on here...
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™