Pond Boss Forums POND CONSTRUCTION Selecting a site Smallish Pond Design

Hi all,

My first post and I'm still reading and absorbing the wonerful info I've found here ...

First, let me describe my location ...
My 5ac parcel sets on a steep ridge. About 3 ac is "usable", and then a steep slope (aka >60% steep ) drops to the other 2ac. My drive way, house and shop are on the "upper" side. My driveway runs down the upper side of the "ridge" and has a 6" PVC culvert that feeds a "mud pit" with seasonal runoff (runoff from neighboring property, gravel road). it actually collects quite a bit of the watershed, but is still seasonal (in the PNW, it rains LOTS during the winter, but is quite dry during the summer).

The "mud pit" (aka future pond site) is about 25' by 50' long. It the input, it's about 1' below the drain, and then narrows to about 4' across and 4' below the drain. Very little to just "fill" the ravine at the end ... (I'll get some pics up very soon, since it's hard to describe).

I'm thinking I could hoe out around 1-2' of muck,
put some fill where the exit narrows, and have a nice 25'x50' pond. With my soil (very sandy), and the smallish size, I'd probably need to put down a liner (and perhaps put 2-4" of "sandy" fill over the liner?)

Being a newb tho I don't want this to become a 25x50 sesspool, or could easily build a "damn" that would just fail in a few years.

Would really appreciate some opinions about the "task" ... I could just make this be a serias of "stream fed pools" (perhaps with recirculating pump for the dry seasons ...

(pics will be in a followup post here in an hour or so ...)

Ok here's some pics ... For "scale", the drain pipe is 8" and the cutoff cedar stump is 30" diameter at the cut.

(click any pic for a "large" version ...

Here's an overview of the site.

It's sorta hard to tell, but the bottom of the drain pipe (on the left) and the top of that stump (on the right) are about level with each other. The dam would be located just about where that stump is (after it's excavated?).

Here's one looking "upgrade". (stump is off camera to the right).

I figure to run a "wall" around the pond that would exclude the huge cedar shown on the right, and follow the rest of the contour (sorta kidney shaped).

Here's one looking downgrade. (drain pipe off camera to the left).

You can just make out the cedar stump, and at that end, the dam would just about go level to the grade on the right. The tree line in the distance is where the dropoff to "down below" is.

This is pretty much maximum flow through (it's been raining 3 solid weeks now). During the summer, the drain pipe goes dry, but that large cedar has tapped an artesian spring that almost keeps it muddy year round ... (I probably have 6-8 springs coming outta the slope "down below")

SOOOOO ...
Now that I've (hopefully) documented the site ... here's the questions ...

Q1) Does this look like a reasonable site for a pond?
I seems like it to me, but I'm a noob. I could just "landscape" in a nice meandering seasonal stream too (lined with bolders, plants, etc). I'd really like to have a "pond" tho for wading into when it's hot, maybe some fish, plants, etc.

Q2) Would I need to "liner"?
I'm guessing that with the sandy soil I have, the answer here is yes ... or else it'll leak dry during the summer (when I really *want* a pond!)

Q3) How "engineered" should the dam be?
I figure it'll be about 4'-5' tall and probably 8' across at the top. I understand I need to have a spillway (could probably C shape that around through). The rest of the damn(sic) design tho I still have things to learn ...

This looks like a reasonable site. First, you need to know what the subsoils are really like. Is there any clay at all?
If there is no clay, a liner may be a good idea.
Engineering is important simply so to know how tall, how wide and how strong it should be. A dam is a water control device. Its job is to receive water, impound it, control excess water, then release it in an orderly fashion. Engineering helps design a spillway, determine the need for a pipe, etc.
The follow up to this is to start by contacting the NRCS (Natural Resource Conservation Service) in the USDA building in your county seat. They can either help engineer the dam or steer you to someone who can.
There's some starting points for you.

R. Currey,
As Lawrance Welk would say "Wonerful, Wonerful, Wonerful and Welcome.
I like your ideas.
My thoughts would be to dig a hole and build up a dam,leaving the center about water level. Then line the hole and extend the liner over the dam, down the back of the dam. Then use your "meandering stream" idea on top of liner starting at the dam and going down the back of the dam.
Idealy this would give you a hole of water and a spillway that wouldn't wash and be appealing.

thx for the quick followup ...

I'm fairly certain of the soil ... it's loam (4"-8") followed by sandy gravel for as deep as I could expect to ever go. In fact about 4' down I found what could be considered beach sand (at the top of this ridge). I also have coal deposits! Nice eh?

It's small enuf area that using a liner won't be too big a deal. Does this make the "design" easier? For example, will a well installed liner negate many of the worries of seep through failure?

Even talking to any gov agency in my county about *any* use of _my_ property is probably going to get me to some supreme court ... I'd prefer to sidestep that.

Here's a e.g of what's happening around me ...
http://www.proprights.org/king_cao.htm ...

*without compenensation for the landowners who now cannot use 50%/65% of THEIR land* ...

Yea ... I think that's exactly my "plan" and glad to hear it's not "off base". Figure I follow the 3-1 rule on the front/back (and both lined), I should be good to hold back this smallish pond?

BTW, ignore my "rant" about property rights. I've read the actual language of the ordinance, and have the loophole to use in court (if I *ever* have too). It's just the other gov employess who don't understand the law that can make my life miserable (and why I don't wanna get them involved).

RC - As Bob points out be sure about the strength of the dam. High water and heavy runoff can put tremendous pressure on the dam's inward face. Maybe someone can find for you the post were a reader's new pond dam in the NY area recently washed out. Hopefully you can see results of substandard dam construction.

As for a small pond, see this link for what can be raised in a small 0.12 ac pond (59'x88'). There are some pretty smart fish raising people here.

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=20;t=002293;p=1#000005

I'm not sure you would want to wade on a liner. You just might poke a hole in it.

"I'm not sure you would want to wade on a liner. You just might poke a hole in it."

This statement is especially true if you have a peg leg.

gotta love deteriorated dialogue...

As long as the dam is structurally sound, and you have a game plan to relieve flood waters, a liner would probably work well. But, be aware, a liner can be undermined, also.

RC - I finally found the post that showed what can happen to an apparently well built dam if construction was not properly performed.

http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=20;t=002087#000009

Bill,

I _do_ understand that proper construction *is* important. At this point I'm still contemplating what I can/should do ...

I'm thinking I may just cleanout the "junk" dumped in the area when the property was developed 40 years ago, some light grading of the perimeter to appear more "natural", and promote the establishment of natural vegetation. I may couple this with a collection of small pools cascading down the grade.

This approach would have the benefit of providing "seasonal interest" (cascading water during rainy months, attractive vegetation otehrwise), and be nearly zero maintenance (aka mom-nature can do what she wants).

Currey, I keep looking at the pictures and asking myself if I would put that area under water. It's beautiful.

You shoulda seen it before the "junk" was taken out ... it's looking MUCH better now.

I'm leaning more towards a natural looking "wet area" with some small paths/stepping stones, moss covered logs, etc. The area is in a highly visible are of the property, and as I get some other areas landscaped, I want that area to look nice. A pond would be a nice addition, but with the input from folks here, I'm guessing that it may be too more work (construction and maintenance) than such a small pond would be worth. (I won't tell anyone yall talked me outta building a pond tho ). Whatever I settle on, I'll post some updates as the area get's land/aqua scaped.

40 years ago when the cleared for buildings, they tossed tons of stumps into "the pit" (we're talking 10 foot diameter old growth cedars stumps cut around 1900). Lots other "waste" also thrown in ... So, those stumps were dead for 60 years, piled into a wet spot for another 40 and still solid 90% though!

For those that like pics ...

Here's a taste of the "start" of the landscaping going on ...

Entrance (needs a bit of thinning me thinks)

House (yup it's back there, perhaps a small trim to the left side would help).


A few during the "harvest"
Entrance (where did that building come from!)

Got wood? (each log is 36')

Goodbye stumps (dem some monsters to remove!)

...love the topo! Pond or no pond, you are at one with nature in 'dem woods. nice lookin' cedar stock??? V nice.