Pond Boss
Posted By: GW Rimming the bank - 07/30/07 01:37 AM
I have questions about the practice of rimming ponds.

One thing I would like to determine is roughly how much difference rimming makes in controlling aquatic weeds. Can you expect to get only 10% of the weeds you would have in an unrimmed pond, or 50%? I know it all depends, but I'm looking for a generalization here.

If a rimmed pond does succeed in being low maintenance with regard to aquatic weeds, what is the maintenance like for land weeds around the shoreline? Would it be as easy maintaining the dry portion of a gradual embankment or is it easier?

If you have a perfectly functioning rimmed bank, what happens if your water level drops 2 or 3 feet and stays in that range for many months, or even a few years? What happens on the exposed rim and how do you maintain it? How does it look? Does it have an effect on fishing from the shoreline?

Then there's the question of diversity. How does a pond that goes from 3 to 12 feet deep compare to one that goes from 0 to 12 feet? I would think that the additional habitat in the 0 to 3 foot range would add a very large degree of diversity. Obviously it adds diversity concerning aquatic plants, but how does that compare to the diversity it adds to animal life? What cost is there to the pond in giving up that habitat for the goal of reducing maintenance?

I would like to hear from people who own or manage ponds where the bank is rimmed and this has created a low maintenance situation with respect to both land and aquatic weeds. These same ponds should also look good because I think aesthetics matter to everyone to some degree. In other words, I'd like to hear some success stories about rimmed ponds.

I'm also curious if some people have gradual embankments and feel that they don't have excessive maintenance issues.
Posted By: Ryan Freeze Re: Rimming the bank - 07/30/07 08:50 PM
I can't offer any experience with rimmed ponds nor have I ever seen one but a I do have 1 bank that is 3:1 above water and it can be a little unnerving mowing it. I am personally much more comfortable with the 5:1 or more gradual slopes.

What exactly is a rimmed pond? Is some sort of soil retaining structure placed forming a straight down drop off like a swimming pool?
Posted By: robo2011 Re: Rimming the bank - 07/30/07 11:48 PM
I have a very gradually sloped bank on about half of the pond, and the alligator weed is very difficult to keep under control. I use a pitchfork to rip it up by the roots, but it grows back fully within a month. It can't tolerate deeper water, more than about 1.5 feet, so I can see an advantage of having steeply sloping banks. The weed does make great habitat for minnows, fry, and frogs, with less shoreline vegetation you would see a decrease in these population.
Posted By: GW Re: Rimming the bank - 07/30/07 11:49 PM
In our area people call a bank rimmed when it has an immediate steep drop to several feet deep. I think it can be a 3:1 ratio and usually it's even steeper.

Mr. H's big pond had examples of both steep and gradual. It's also a pond which has had very little management other than regular mowing and occasional herbicides applied to the steeper banks where the mower can't safely reach.

This is how the "rimmed" bank looked last February, but the weeds are thicker now:



This side of the pond was left with the existing gradual slope. In this area Mr. H can run his Bushhog right up to the shoreline. I've never seen anything growing there other than the Bahia (?) that is the dominant grass. There are also not many more aquatic weeds in the shallow water in his pond, but I understand it will vary in each pond. (That is my faithful companion Flop Ear Dog) \:\)


I'm not trying to prove that steep banks aren't the best approach. A big factor influencing me now is the large number of ponds around here that are 5 feet below full pool. Most of them are steeply rimmed and in most cases it looks pretty ugly.
Posted By: GW Re: Rimming the bank - 07/31/07 12:00 AM
robo2011, your example interests me for a few reasons. If do this design and I'm holding the pond at the lower level I might end up with a similar Alligator weed problem. The difference would be that I could close the lower siphon and during the wet season the weeds would be covered with 2 or 3 feet of additional water, killing them.

Then after holding the water at the high drain level for several months I might get the weed growing again. This time I could open the lower drain and leave the weeds high and dry.

I'm sure there would still be problems controlling aquatic weeds with this design, but I'm trying to get to a point where I can intelligently weigh the variables. One thing I'm fairly confident of at this time is that a gradual bank will be noticeably easier to maintain.

I appreciate all of your personal experiences very much.
Posted By: ewest Re: Rimming the bank - 07/31/07 01:01 AM
GW contemplate this pic wrt you question. Pic by Bill Cody. \:\)


Posted By: GW Re: Rimming the bank - 07/31/07 01:19 AM
Well, I don't see any weeds....



edit: Wait! There's a Thermos jug.

edit 2: Concrete is the only way to eliminate weeds?

This pond/lake was drained/lowered for a purpose related to some of mine?
Posted By: Theo Gallus Re: Rimming the bank - 07/31/07 09:50 AM
Is that a pond dock or a loading dock?
Posted By: bobad Re: Rimming the bank - 07/31/07 01:46 PM
 Quote:
Originally posted by GW:
edit 2: Concrete is the only way to eliminate weeds?
Hmmmm... 1" thick concrete multiplied by 64000 sq feet, multiplied by cost per yard, plus cost of 100 concrete finishers...

Uh, never mind. Weeds aren't so bad.
Posted By: ewest Re: Rimming the bank - 07/31/07 02:03 PM
It is just what it says a "concrete beach". It is used to have an easy to get in and out method (and swim etc) for ponds with steep sides. With it plus steep sides you have few weeds. With this you have easy entry/exit and a clean hard place to wade , float etc.
Posted By: dave in el dorado ca Re: Rimming the bank - 07/31/07 02:09 PM
concrete beach.....i really like that.

BTW GW, i went with really steep sides all the way around, my water level uncontrollably drops 6 feet every summer, it is impossible to mow anywhere near the pond, the strip of open space caused by the dropping water (between water's edge and former high water mark) is the only open access to walk around the pond when not full (well you actually stumble and tread lightly on steep slopes around the pond). it is a wild, woolly, ugly, but beautiful mess....its my pond and i love it for all its faults. i dont spend a second worrying about weeds. i really like looking at pics of you guys back east with your manicured lawns all the way to pond, neat as a pin......just not gonna happen that way in el dorado.

good luck, you have a cool design.
Posted By: robo2011 Re: Rimming the bank - 07/31/07 02:40 PM
GW:

Alligator weed will die in deep water, but it can survive, even thrive out of the water, mine has actually spread out of the water and climbed up the bank about 5 to 10 feet. If you stay on top of the weed problems from the beginning, it won't get to bad.
Alligator weed does die quickly when in deep water, when we got about 3 or 4 inches of rain in a two week period the water level rose about 6 inches, and all the deepest weed turned brown and began to die off.
Good luck.
Posted By: cheyenne19 Re: Rimming the bank - 07/31/07 05:21 PM
My pond has a steep bank all the way around it. 3:1 and in some places 2:1 make it very interesting to mow. On the inside of the pond we used rip rap to control erosion. It also controls weeds.
Posted By: GW Re: Rimming the bank - 07/31/07 07:17 PM
D.I.E.D, we're building a swamp here man!

I would like to be able to mow the banks so that I can manage for native grasses if possible. I'm only concerned about any weeds, land or water, when they get to a point were they adversely effect other important systems. I did mention aesthetics as a consideration, but in our case that doesn't refer to manicuring anything like a lawn (not that anything wrong with that). We're trying to create a habitat that looks as "natural" as possible, maybe like beavers made it.

That's it really, I would be happy if this pond looked like it was formed by beavers. If there were significant and clear advantages to rimming the pond I would do it, but I still have doubts that it really helps very much.

Just to clarify, I don't find ponds with weedy and/or steep banks unappealing. As you can see (in my dual level pond thread), my design has both gradual and steep grades depending on the water level. Mostly I'm trying to understand any advantages before I commit to the dozers.
Posted By: Ryan Freeze Re: Rimming the bank - 07/31/07 07:51 PM
Above the water line the banks can be fairly flat for easy mowing. Below the water line most recommend 3:1 to discourage weed growth. I have two sides where the slope is 3:1 and two at 5:1 below the water line and have found no significant difference where submerged and emergent plants grow but this is only year 5 for me and I do manage for a weedless pond. Above the water level the banks vary from nearly flat with very moderat swales for surface drainage to 3:1. If I had it to do over I would have built the 3:1 bank at a more gradual slope for safer mowing. One nice thing about steeper banks is less mud is exposed as the water level drops in dry weather. I think any steeper than 3:1 would be a hazard if someone were to fall in because 3:1 is about as steep as I can climb out of when swimming.
Posted By: george1 Re: Rimming the bank - 07/31/07 07:57 PM
GW, a lot of folks like cattails - I don't.

It's been mentioned on this forum before, and I find it to be the case in our ponds, cattails don't grow well on solid clay as they do on sandy soil.

When we had invasive cattails, they were growing on sandy soils.
When we deepened this area, the pond bottom is hard clay, and the cattail problem is solved.
By deeper water?
By clay soil?
Both?

Your desired aquatic vegetation may be as dependent upon soil type as engineering.

"It all depends"...
\:\)

 Quote:
Originally posted by george1:
 Quote:
Originally posted by GW:
........
To make it easier to design I've been thinking in terms of a pond within a pond...............

Any ideas or comments would be appreciated.

GW, following photos illustrates the way we handled a “pond within a pond.

Not conceived nor planned on an engineering basis, but by necessity to control massive cattail invasion created by leaving a “shelf” on the upper end, perhaps similar to your design.


Before.. Cattails on “shelf “area.







Posted By: Theo Gallus Re: Rimming the bank - 07/31/07 09:56 PM
Clay vs. sand - good question, george.

My bottom and edges are all clay and cattails have never taken hold. I pull 3 or 4 small plants a year, and that's all the control that has been needed.
Posted By: GW Re: Rimming the bank - 07/31/07 10:05 PM
Thanks George, I hadn't read about the soils influence. Maybe I can get the contractor to add some extra clay around the perimeter and possibly compact it more.

Ryan, do you use herbicides for controlling aquatics?

Robo, do you find that the Alligator weed is accceptable on the dry banks? I guess it would be easy enough to kill on the dry areas if you wanted to.

Cheyenne, thanks for the rip rap idea. I wonder if smaller rock would be effective. I want to be prepared for this pond to be 5 feet low at times and smaller rock seems like it would be better material for a bank to fish from. Rock also seems like it would enhance the habitat for some animals.
Posted By: cheyenne19 Re: Rimming the bank - 08/01/07 11:49 AM
Tightly packed rock would work very well. It would depend some on the size, but it should work well.
Posted By: GW Re: Rimming the bank - 08/01/07 01:20 PM
Maybe we've come up with a new strategy for limiting aquatic weeds - form a gradual slope into the water and line it with compacted rock and clay.

It might cost more than rimming, but I think it would give an easier shoreline to maintain and it would likely adjust to lower water levels more efficiently.

I might run this by our contractor.
Posted By: Ryan Freeze Re: Rimming the bank - 08/01/07 03:41 PM
I use Cutrine plus to control filamentous algae as needed when conditions are not suitable for tilapia, or if tilapia are unavailable. It appears that if tilapia are readily available I could limit algae treatments to a single application in the spring and fall and be algae free. I have a very small 2'x5'patch of cattails growing out of a moist bare area between the limestone border and lawn. I don't mind a few and allow them to grow. I do cut off the flower spikes before the go to seed. They don't grow throught the geotextile fabric and limestone and can't compete in the lawn. This year, with excessively low water levels, some grasses have started to grow between the rocks that were below water level and have some silt between them. They are easily pulled or spot treated with a herbicide.
Posted By: Ryan Freeze Re: Rimming the bank - 08/01/07 03:56 PM
If you look past the dock you can see the easily maintained edge between the lawn and the stone border. The stone is lower than the mower deck height allowing me to mow over the line. A couple of spot treatments of herbicide are visible at stone/lawn trasition, spot treatments are done twice per year. The greenery at the water's edge is water hyacinth that was planted as an annual in an attempt to take up excess nutrients and form some shade. The hyacinth hasn't been noticably effective. It is a very invasive plant in warmer climates but hasn't performed well in Ohio and it is unlikely I will plant it again.


Posted By: robo2011 Re: Rimming the bank - 08/01/07 05:32 PM
GW:

Yeah, the alligator weed can just be mowed when it is up exposed on the dry bank, but if the water level rises, it already has a head start on other plants.
Posted By: GW Re: Rimming the bank - 08/01/07 06:03 PM
I imagine that if the water level was held at a lower level it would be good to kill the Alligator weed and replant something desirable.

robo, I'm curious whether you would redo your gradual banks at this point if there was no cost or inconvenience involved.
Posted By: Ryan Freeze Re: Rimming the bank - 08/01/07 08:15 PM
The upper picture illustrates what I consider a difficult to maintain bank. The steep grade makes it more difficult to establish desireable grasses, promoting erosion and weeds. It is also more dangerous to operate machinery on and not as comfortable to walk around. The lower illustration still has the advantage of being steep below water level to discourage aquatic weed growth but is much easier to establish grass, mow and walk around. At very wet times, the ground above water level in the lower picture may get wet and mushy making it a little more difficult to mow but a wet steep bank is slippery both by foot and dangerous for operating equipment on.

Posted By: GW Re: Rimming the bank - 08/01/07 10:41 PM
Ryan, you not have seen my previous thread which shows my proposed pond contour: Considerations for a dual level pond

My diagram looks very similar to your second rendering.


I think that often people do design their ponds similar to your second example. The problems I've observed result from lower than optimum water levels, either from drought, design issues, or from pond liners that might slowly leak making the planned water level unrealistic.

That's the reason I'm currently considering a gradual slope beginning well above the highest waterline and continuing straight down to maybe 5 or 6 feet below the highest level.

One clear advantage to that consistent slope is that regardless of the water level, the bank can be maintained easily and the above water environment made to look "natural". In other words in an extended low water situation someone wouldn't look at the pond and realize that it was low. After all, who hasn't had to deal with low water? Why not design a pond to anticipate that?

I know that by eliminating the fast drop off into deep water other problems may be encouraged, but I'm looking for some good evidence that that's true. If I'm going to give up the easy maintenance of a gradual slope, I want to try to quantify the advantages I'm gaining. Also, it's not that I'm prioritizing looks over function, but before I give up a good looking pond with an easy to access shoreline, I want to know what functional advantage I'm gaining.
Posted By: GW Re: Rimming the bank - 08/02/07 11:55 AM
Does anyone have clue about what the cost might be to have 100 yards of rock delivered, maybe 2 inch or bigger?

I figured it this way:

1200 linear feet by 8 feet wide = 9600 sq.ft.

9600 X .25 feet (3 inches) = 2400 cubic feet

2400 cf. divided by 27 (cf/yard) = 88 cubic yards
Posted By: BarO Re: Rimming the bank - 08/02/07 01:15 PM
I wouldn't be putting 1-2" river rock on my place now. It was $50/yd in Tyler this past week.
Posted By: Theo Gallus Re: Rimming the bank - 08/02/07 03:28 PM
GW, I don't think aggregate prices necessarily travel well around the country, especially since so much of the delivered cost depends upon how far they have to truck it to your site.

If I were you, I'd inquire at the different gravel-tyes places near you and see what their delivered prices are for different materials that would be suitable for you (limestone, sorted bankrun gravel, etc.).
Posted By: GW Re: Rimming the bank - 08/02/07 04:00 PM
Would there be a preferred type of rock, or certain ones that wouldn't work?
Posted By: robo2011 Re: Rimming the bank - 08/02/07 05:27 PM
GW:

I am actually in the process of raising the water level which will help this problem. The lengenthed dam will raise the water level several feet, eliminating this slope in most areas. The person who built the pond located the spillway much to far below the pond's optimal bank. The increased slope will hopefully make weed cleaning much easier.
Posted By: GW Re: Rimming the bank - 08/02/07 05:35 PM
So robo, you're eliminating the gradual slope and replacing it with a steep slope? Did you say you had other parts of the pond where you already have steep banks into the water? If so, I assume you've had better luck with the steeply graded banks in terms of aquatic weed control.
Posted By: Shorty Re: Rimming the bank - 08/02/07 05:37 PM
GW - we have steep banks along our dam and the milfoil grows all the way to the surface in 7-9 ft of water.

Did I mention that the weeds also grow inbetween the the rocks on the dam too.
Posted By: rockytopper Re: Rimming the bank - 08/02/07 06:47 PM
Shorty I concur. The hand books says to cut the banks down steep to 3 ft to control weeds. My experience has shown it don't matter weeds are going to grow no matter what and as you pointed out weeds will find there way thru rocks. If your putting rocks for weed control I whould think you need to put down some sort of mat or weed barrier before the rocks go in. I built a retaining wall that is straight down to 3 feet and the aquatic weeds are now thicker in front of it than the natural 3:1 sloped banks next to it. I just spent 275$ on aquatic herb from one of the nice vendors that support pond boss. I haven't used it yet it still hasn't quit raining in our parts. The best defense in my mind for keeping the bank mantained is gentally sloped banks 5 to 1 or less as pointed out above so that you can safely mow as close to the edge as possible.
Posted By: bobguillory Re: Rimming the bank - 08/02/07 07:17 PM
Anyone have any cool toys to mow steep banks on a large scale? ie 20 acres.
Posted By: rockytopper Re: Rimming the bank - 08/02/07 07:31 PM
Bob standard equipment and lots of guts \:D
Posted By: Shorty Re: Rimming the bank - 08/02/07 07:40 PM
rt - keep in mind that our pond is 40+ years old, there is sediment that has collected in the crevices of the rocks that the milfoil can root itself in. We also have regular sechi disc readings in the 7-8ft range which promotes deep weed growth. I have been trying to figure out how to keep the water clarity down so the weeds don't grow so deep in our pond. BTW - the water clarity and weed growth in our pond is an "anomaly" in eastern NE.

Here are some of the reasons our water is so clear and why the weeds grow so deep our pond.

1. Large cedar trees line both the north and south shore which prevents strong winds from stirring up the sediment along the banks.

2. 2/3 of our pond has rock lined banks that prevent sediment from getting stirred up by the wind.

3. We have prairie grass and broam grass surrounding the pond before any runoff enters the pond.

4. We have Eurasian Milfoil which over time creates a self feeding loop in which the water calms and clears, as it clears, this weed grows out deeper and deeper. Excess nutrients feed the mildfoil and coontail growth rather than feeding an algea bloom every year.

I hear you on the weed control, we just poured almost $1200.00 into the water in the last month.
Posted By: TOM G Re: Rimming the bank - 08/02/07 07:44 PM
Bob install training wheels on your tractor...still need lots of guts though \:D \:D
Posted By: rockytopper Re: Rimming the bank - 08/02/07 08:44 PM
Related to this subject, I have found on my new pond some of the banks are too flat. The contractor started cutting at the full pool staked waterline which is norm. I have an area where the natural grade is only about a 1/2 inch above pool. In this area about 60 yards long or so it stays muddy about 10 ft from the waters edge, Not enough to kill weeds but too wet to put the tractor on it to mow. So I have this strip that I can't maintain. I'm either going to have to build it up or cut the edge with a back hoe further back to higher grade to fix this issue.
Posted By: robo2011 Re: Rimming the bank - 08/02/07 09:38 PM
GW:

Oh yes, I have a section of the pond next to the dam that is currently steep, before the water level rises, and have no weed problems. The weed can barely grow at all. It is really steep, 1 to 1, until it levels off at about 3 foot. Much too steep, it is very hard to wade in it, I've lost my balance many times and fallen in.
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