I'm in the planning stages for a new earthen pond on a couple acre property I've recently acquired. The property has a gentle slope, and in one corner has I space I feel may be ideal for a small pond. I'd hoped to make the pond .08 acres (surface area) with a max depth of 10'. Volume at this size is .33 acre-ft.

According to the USDA's 'Ponds, Planning, Design, and Construction' my area would ideally have 12acres of runoff area for each acre-ft of pond. My watershed feeding this pond is only about 2 acres - according to what I've read at least 4 acres would be ideal.

My questions are:
1) In your opinion, would it be better to go with a smaller pond that will hopefully stay more full, or a larger pond that might fill up in the spring but evaporate quite a bit over the summer?
2) Do you know of any other factors that might positively influence this issue I'm seeing regarding less than ideal drainage area feeding the area? I have clay soil which should hold water nicely.
3) Any other thoughts you'd care to share?

I'm attaching a screenshot of my topographic property map with drainage lines specified.
My soil profile (unconfirmed at this point.. will test in the spring) is below."

My goal is to have a pond to provide water access and for recreation. This is an off-grid operation.

Thanks and I'm excited to have joined this group! -Chris



[quote]
Itasca County, Minnesota
626B—Suomi silt loam, 1 to 8 percent slopes
Map Unit Setting
National map unit symbol: fcmg
Elevation: 980 to 1,310 feet
Mean annual precipitation: 20 to 27 inches
Mean annual air temperature: 37 to 41 degrees F
Frost-free period: 95 to 105 days
Farmland classification: All areas are prime farmland
Map Unit Composition
Suomi and similar soils: 90 percent
Minor components: 10 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Suomi
Setting
Landform: Lake plains
Landform position (two-dimensional): Summit, backslope
Down-slope shape: Linear
Across-slope shape: Linear
Parent material: Silty and clayey till
Typical profile
A - 0 to 3 inches: silt loam
E,E/B,Bt - 3 to 36 inches: clay
C - 36 to 60 inches: clay
Properties and qualities
Slope: 1 to 8 percent
Depth to restrictive feature: More than 80 inches
Drainage class: Moderately well drained
Capacity of the most limiting layer to transmit water (Ksat): Very low to moderately low (0.00 to 0.14 in/hr)
Depth to water table: About 30 inches
Frequency of flooding: None
Frequency of ponding: None
Calcium carbonate, maximum content: 35 percent
Available water supply, 0 to 60 inches: Moderate (about 9.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: D
Ecological site: F057XY020MN - Fine Upland Mesic Hardwood Forest
Forage suitability group: Sloping Upland, Acid (G088XN006MN)
Other vegetative classification: Sloping Upland, Acid (G088XN006MN)
Hydric soil rating: No
[/quote

Attached Images
pond.PNG drainage requirements.png
Last edited by ChrisOh; 01/23/22 09:38 PM.