Question Regarding Correct Weir Configuration in SWAT+ Editor and SWAT+ Toolbox

[rick liao]

Dear SWAT+ Development Team,

I am currently developing a paddy field model using SWAT+PADDY and SWAT+ Editor v3.0.12 rev61.0.1 /Toolboxv3.2 rev61.0.1. I would like to ask for your advice regarding the correct procedure for configuring a weir in a paddy HRU.

I have tested several approaches to control the weir operation, including:

Using a Decision Table to control the weir operation.
Using the Management Operation Schedule to define weir operations.
Configuring the weir through the SWAT+ Toolbox.

However, when I use either the Decision Table or the Management Operation Schedule to change the weir settings, there is no apparent change in the simulation results. The weir operation does not seem to affect the simulated water level or drainage as expected.

More importantly, when I configure the weir through the SWAT+ Toolbox, the irrigation settings appear to become ineffective. In other words, after adding/configuring the weir, the irrigation operation that previously worked correctly no longer produces the expected irrigation input to the paddy field.

Therefore, I would like to clarify the correct workflow for setting up a weir in SWAT+PADDY.

Specifically, I would appreciate your guidance on the following questions:

Where should the weir be configured first: in the SWAT+ Editor, Management Operation Schedule, Decision Table, or SWAT+ Toolbox?
Is there a specific object or input file that must be created or configured before the weir can be operated by a Decision Table or Management Operation Schedule?
Can the weir operation be controlled directly through a Decision Table or Management Operation Schedule in a paddy HRU?
Is there a conflict between the weir configuration in the Toolbox and the irrigation operation in SWAT+PADDY?
What is the recommended configuration procedure if I want to simulate both irrigation and weir-controlled drainage in the same paddy HRU?
Are there any specific input files or parameters that I should check to ensure that the weir operation is actually being read by the model?

My objective is to simulate a realistic paddy water management system in Taiwan, where irrigation and weir-controlled drainage need to operate together during different rice growth stages.

I would be very grateful if you could provide a recommended step-by-step configuration procedure or a simple example project/input configuration showing how irrigation and weir operations should be defined together.

Thank you very much for your help.

Best regards,

Rick Liao

[廖顯綸（顯綸）]

Dear SWAT+ Development Team,

I am currently developing a paddy field model using SWAT+ Editor rev61.0.1/Toolbox v3.2  rev61.0.1. I would like to ask for your advice regarding the correct procedure for configuring a weir in a paddy HRU.