	Product(s):	PondPack
	Version(s):	N\A
	Environment:	N\A
	Area:	Modeling

Introduction

Pond surface materials may vary with elevation. This article discusses how to model varying pond infiltration rates that correspond to the water surface elevation using an outlet rating table.

Steps to Accomplish

1. Set the pond to use the infiltration method "No Infiltration".

2. Create a pond outlet that leads directly to an outfall.

3. Create a composite outlet structure that has a user defined rating table with the elevation and corresponding (infiltration) flow.

a. Open the Components menu and select Composite Outlet Structures

b. Click the New icon, select Composite Outlet Structure then enter the properties for the Composite Outlet Structure. Tailwater Type should be set to Free Outfall.

c. With the new Composite Outlet Structure selected, click the New icon again select User Defined Rating Table and enter the properties for the User Defined Rating Table. Set Flow Direction to Forward Flow Only.

d. Enter the elevation and corresponding flow values in the User Defined Rating Curve.

4. Set the pond outlet to use this composite outlet structure.

5. Set the outfall's Boundary Condition Type to Free outfall

6. Compute the model.

7. Graph the flow in both pond outlets to compare the infiltration and flow out of the pond over time.

How to vary pond infiltration rate with water surface elevation using an outlet rating table

Introduction

Steps to Accomplish

See Also