Hello WEAP community,

I'm working with a WEAP-MODFLOW model and need guidance on which values to use for water balance reporting.

The Problem: MODFLOW output files (.ccf) show much higher river-aquifer exchange flows than WEAP direct results. The difference is 6-10 times. I've verified my calculations are correct (units, spatial aggregation, sign conventions, linkage, topology, temporal alignment, no double-counting).

What I Need to Know:

1. Why are WEAP values lower than MODFLOW?
- Does WEAP filter flows based on water allocation logic?
- Does WEAP aggregate MODFLOW cells differently?

2. Which values should I report?
- For regulatory water balance reports, should I use:
- MODFLOW values (complete physical exchange)?
- WEAP values (filtered/processed)?

3. Which WEAP output file represents the actual groundwater-surface water exchange?

4. Is this normal behavior? Has anyone dealt with this issue?

Thank you for any guidance!
Carlos