MyPond capability
Pond soil and bedrock analysis
Read the soil under the pond before you decide why it behaves the way it does.
MyPond reads the USDA soil survey under a traced pond and reports it horizon by horizon. For each mapped soil layer you get texture class, percent clay, silt and sand, saturated hydraulic conductivity, depth to water table, depth to bedrock, parent material, and the USDA pond suitability and reservoir ratings. Underneath that, mapped bedrock geology carries rock class, dominant lithology, age, and whether the unit is carbonate. Together these answer whether a pond can be expected to hold water and whether its chemistry will buffer itself.
Inputs, analysis, outputs
What you provide
- The pond footprint
- The traced shoreline, or the delineated watershed for the upstream version.
What MyPond does
- Map unit identification
- The soil map units intersecting the polygon are identified, and where several occur under one pond they are reported separately along with an area weighted summary, because a pond sitting on two map units is a pond with two behaviors.
- Horizon by horizon properties
- For each mapped horizon MyPond reports its depth range, texture class, the clay, silt and sand percentages, and saturated hydraulic conductivity, which is the measured rate water moves through that layer when it is saturated.
- Site constraints
- Depth to seasonal high water table and depth to bedrock, both of which decide whether a pond can be deepened and whether it will intercept groundwater.
- Bedrock characterization
- The mapped bedrock unit and its lithology, with a carbonate flag. Carbonate bedrock supplies the alkalinity and hardness that let a pond resist pH swings.
What you get back
- Dominant soil series and texture class
- Plus every map unit under the footprint.
- Percent clay, silt and sand
- By horizon and as an area weighted summary.
- Saturated hydraulic conductivity
- In micrometers per second, by horizon.
- Depth to water table and depth to bedrock
- In feet.
- USDA pond suitability and reservoir ratings
- The published interpretive ratings for the mapped soils.
- Parent material and mineralogy class
- What the soil weathered from.
- Bedrock unit, lithology, age and carbonate flag
- For the pond and for the watershed.
How it works
What saturated hydraulic conductivity tells you
It is the rate water moves through a saturated soil layer. Low values in the horizons at pond depth mean the basin can hold water; high values mean it will leak unless something else is sealing it. It is more useful than percent clay alone, because clay that is cracked, structured or full of coarse fragments transmits water faster than its clay percentage suggests.
Why the horizon matters, not just the surface
A pond is excavated into a soil profile, so the layer that matters is whichever horizon sits at the depth of the basin, not the topsoil. A site with a clay surface over sand at four feet is a leaking pond waiting to happen, and only a horizon by horizon read shows it.
What a soil survey is and is not
SSURGO is mapped at a survey scale, so a map unit describes the dominant soils across an area rather than a boring log at one point. It is the right tool for whether a site is plausible and what to expect, and the wrong tool for a final engineering decision on a dam. MyPond reports the map units rather than averaging them away so the variability stays visible.
Where the data comes from
- USDA SSURGO
- The Soil Survey Geographic database, the USDA mapping of soil map units across the United States. MyPond reads the map units under the pond footprint and their horizon by horizon properties: texture class, percent clay, silt and sand, saturated hydraulic conductivity, depth to water table, and depth to bedrock.
- Bedrock geology mapping
- Mapped bedrock units under the pond and its watershed, carrying rock class, dominant lithology, geologic age, and whether the unit is carbonate. Carbonate bedrock is the single best predictor of a pond that buffers itself, which changes what treatments will and will not hold.
Common questions
Can soil data tell me why my pond is leaking?
It can tell you whether the soils at pond depth are capable of holding water. A permeable horizon at basin depth is a strong explanation. Soils that should hold water point the investigation elsewhere, usually toward the dam, an outlet structure or animal burrows.
Does MyPond report soil for the watershed too?
Yes, the same analysis runs over the delineated drainage area.
Why does carbonate bedrock matter for a pond?
Carbonate rock dissolves into alkalinity and hardness, which buffer pH. A pond over carbonate resists the daily pH swings that come with heavy algae growth. A pond over granite or acidic sandstone often has almost no buffering and swings hard.
Related
MyPond is built by Natural Waterscapes. See live data from a real pond, or what it costs.