| Product(s): | PondPack |
| Version(s): | 10.02.00.01 |
| Area: | Calculations |
Problem
When graphing the Infiltration result field for a pond whose connected outlet tailwater is set to “interconnected ponds” (ICPM), the graph does not look right and does not appear to correspond with the water surface elevation and expected. This happens for ponds that use “constant infiltration” as the infiltration type. For example after a certain time, the infiltration rate decreases even though the pond water surface elevation increases, and the water surface elevation may appear to stay flat with no continued infiltration.
Solution
First, ensure that you are using the latest version + patch, as there have been some important fixes to infiltration (with ICPM) in a patch to version 10.02.00.01 (reference #1041830 and #1069499). If you are using 10.02.00.01, please contact Technical Support to obtain the latest cumulative patch set, to get the fix. When a newer PondPack version is available, upgrading to that version will also include the fix. For information on download the latest versions, see: Downloading OpenFlows Software
If the problem still occurs, you may have encountered a known limitation with the ICPM algorithm. During the ICPM calculations, the exact pond water surface elevation cannot be known at a given time, because of the way in which interpolation is done when the infiltration rate is applied. So, PondPack must make the following assumptions:
- Desired constant infiltration rate is greater than the pond inflow rate: in this case, the infiltration calculations and results will use the Inflow rate value, regardless of the water surface elevation in the pond (empty or not).
- Desired constant infiltration rate is less than the pond inflow rate: in this case, the infiltration calculations and results will use the desired constant infiltration rate, regardless of the water surface elevation in the pond (empty or not).