Pond Pump Size Question

[Steve Shapson]

I have a pond 25x25 feet by 2 feet depth. A large stream 40 feet long with
a 4 foot height flows into it. How do I figure out what size underwater
pump I will need to make the stream flow fast?

Are there site which help with this math?

--
Steve Shapson

[Cybe R. Wizard]

On Sat, 27 Dec 2003 15:24:03 GMT
"Steve Shapson" > wrote:

> I have a pond 25x25 feet by 2 feet depth. A large stream 40 feet long
> with a 4 foot height flows into it. How do I figure out what size
> underwater pump I will need to make the stream flow fast?
>
> Are there site which help with this math?
>
> Steve Shapson
>
Forget the math.

There are several things that affect the flow of a stream. Fall ratio,
pump capacity, cross section area of the stream bed, and obstructions,
among possibly others. You have a four in forty fall, not really good
for strong flow. You haven't mentioned the cross section area of the
stream bed, nor any obstructions you may have in the bed. If you have a
pump at all, try it in the stream and see what it's like. Estimate the
flow you want as opposed to the flow you will have. As a helper, maybe
throw a hose in with the pump outflow and see if the increase is
observable. Maybe fill some 5 gallon buckets and pour into the stream
head to estimate <the amount of water you will need>/<time> to achieve
what you want. I guess what I'm trying to say is that there is no
substitute for experience /in your stream bed/ to find out what you
want. I'd think about adding several small ponds (wonderful
obstructions!) along that forty foot distance to reduce the total
distance your stream(s) must flow and, at the same time, increasing the
fall ratio. The same thing may be achieved using an occasional
obstruction. Some like the look of a gravel/rock stream bed and it's
pretty easy to adjust your flow thereby. Otherwise, narrowing of the
stream will obviously increase flow rate, but may also require
increasing the stream bed depth. You will also want to consider what
will happen to the stream-held water when the pump is turned off. Left
to itself, a full pond with running stream will overflow when there is
no pump running. One solution is to make an overflow bog area which only
fills when the pump is off. This also encourages turning the pump off
occasionally so the bog plants can get a good watering.

Cybe R. Wizard
--
Unofficial "Wizard of Odds," A.H.P.
Original PORG "Water Wizard," R.P.
"Wize(ned) Wizard," A.P.F-P-Y.
Barely Tolerated Wizard, A.J.L & A.A.L

[~ jan JJsPond.us]

I can't answer any better than Cybe. I do remember some mathematical thing
of 100 gallons per 1 inch of width for 1 inches deep of water. Even then I
think experience and playing around are going to pay off better. (In any
other newsgroup that last sentence.....<gasp>). ~ jan :o)


>On Sat, 27 Dec 2003 15:24:03 GMT
>"Steve Shapson" > wrote:
>
>> I have a pond 25x25 feet by 2 feet depth. A large stream 40 feet long
>> with a 4 foot height flows into it. How do I figure out what size
>> underwater pump I will need to make the stream flow fast?
>>
>> Are there site which help with this math?
>>
>> Steve Shapson
>>
>Forget the math.
>
>There are several things that affect the flow of a stream. Fall ratio,
>pump capacity, cross section area of the stream bed, and obstructions,
>among possibly others. You have a four in forty fall, not really good
>for strong flow. You haven't mentioned the cross section area of the
>stream bed, nor any obstructions you may have in the bed. If you have a
>pump at all, try it in the stream and see what it's like. Estimate the
>flow you want as opposed to the flow you will have. As a helper, maybe
>throw a hose in with the pump outflow and see if the increase is
>observable. Maybe fill some 5 gallon buckets and pour into the stream
>head to estimate <the amount of water you will need>/<time> to achieve
>what you want. I guess what I'm trying to say is that there is no
>substitute for experience /in your stream bed/ to find out what you
>want. I'd think about adding several small ponds (wonderful
>obstructions!) along that forty foot distance to reduce the total
>distance your stream(s) must flow and, at the same time, increasing the
>fall ratio. The same thing may be achieved using an occasional
>obstruction. Some like the look of a gravel/rock stream bed and it's
>pretty easy to adjust your flow thereby. Otherwise, narrowing of the
>stream will obviously increase flow rate, but may also require
>increasing the stream bed depth. You will also want to consider what
>will happen to the stream-held water when the pump is turned off. Left
>to itself, a full pond with running stream will overflow when there is
>no pump running. One solution is to make an overflow bog area which only
>fills when the pump is off. This also encourages turning the pump off
>occasionally so the bog plants can get a good watering.
>
>Cybe R. Wizard

See my ponds thru the seasons and/or my filter design:
http://users.owt.com/jjspond/

~Keep 'em Defrosted~
Tri-Cities, WA Zone 7a
To e-mail see website

[Chagoi]

Steve Shapson wrote:

> I have a pond 25x25 feet by 2 feet depth. A large stream 40 feet long with
> a 4 foot height flows into it. How do I figure out what size underwater
> pump I will need to make the stream flow fast?
>
> Are there site which help with this math?
>
You might want to use this info from Pondusa ( http://www.pondusa.com )
as a starting point.

Waterfall Weir Rates

http://www.pondusa.com/hints.htm

I will be experimenting with a stream, this summer.

How wide is the stream?
@ the beginning___
@ the end___
and how deep is it ?
@ the beginning___
@ the end ___
any deep areas in the stream
How big are the areas?

Any pics?


&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
your pond volume
25 X 25 X2 X 7.5 = 9375 gal
25 X 25 = 625 sq. ft
625 X 2 = 1250 cu. ft
1250 X 7.5 = 9375 gal

stream volume
40 X ? X ? X 7.5= ? gals

any measurements in inches must be converted to feet @ 1" = .0835'
1 cubic foot holds 7.5 gals


I have tried to do some calculating below "please don't shoot me if i'm
wrong"
I'm only fresh out of school :~)
Well! 33 years may not be that fresh. ;~)

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
examples:
very rough calculations:
using the 12" weir from the chart as a guide.
If you want a stream flow of about 1" in depth
and say your stream starts out at 14"wide.
A starting point would be 375GPH per Inch of width

375 X 14 = 5250GPH

stream volume:
40' long
2" deep = .167'
14" wide = 1.167'

40 X .167 X 1.167 X 7.5 =approx 60 gal

40 x .167 = 6.68 sq. ft.
6.68 X 1.167 = 7.796 cu.ft.
7.796 X 7.5 = 58.64 gal

60 gal. = 8.0 cu ft

If the stream ( using the above measurements) were shut down you would
need room in the pond
to hold an extra 60 +gal of water. in a pond like yours 625 sq. ft. 2'
deep and 9375gals.

The pond would rise less than 3/16"

Method #1 (gallons)

9375 gal / 24" = 390 gal / inch of depth
195 gal / 1/2 "
97 gal / 1/4 "
73.5 gal / 3/16 "
60+ gal (example "your pond") less than
3/16" rise in pond depth
49 gal / 2/16 or1/8 "
24.5 gal 1/16 "

Method #2 (square foot)

8cu. ft = 96 sq.' 1 inch deep
192 sq' 1/2 inch deep
384 sq' 1/4" deep
512 sq' 3/16" deep
625 sq' (Example "your pond") less than 3/16" rise
in pond depth
768 sq' 1/8" deep
1563 sq' 1/16" deep

Chagoi

http://ourkoipond.com