SWAT+ water balance issue: low runoff and high evapotranspiration

[Ibtissam Amegdoul]

Hello,

I am working on a SWAT+ model and encountering an issue with unrealistic hydrological results.

Although all inputs were prepared (DEM, land use, soil, climate data) and the model runs correctly, I obtain:

• Very low surface runoff and water yield
• Almost all precipitation converted to evapotranspiration
• Nearly zero groundwater contribution
• Simulated streamflow close to zero, while observed data show significant peaks
• NSE < 0 and very low R²

The water balance confirms this behavior (ET ≈ precipitation).

I have already checked climate data, units, station locations, and setup, but I cannot identify the source of the problem.

Any suggestions on what to investigate would be greatly appreciated.

Thank you!