Designing ponds
Design a pond with customized parameters into your drainage system model.
Step-by-step:
When a catchment is overlaid with an impermeable surface, such as concrete or tarmac, it will create more (and faster) runoff. A traditional solution to this problem is to build a storage or attenuation structure (i.e., a pond) upstream of the discharge point, store the water there, and release it slowly into the receiving watercourse.
- In the model, double-click pipe 016 to open the Connections dialog box and view its attributes.
- Note the Upstream Cover Elevation for the selected pipe.
- Close the Connections dialog box.
- In the Tree View, right-click the Surface node and select Load Surface.
- In the Surface Data dialog box, click Load From.
- Select the surface data file import surface trimmed.iddx and click Open.
- A notification appears, asking if you want to update all or keep all existing surface data, or manually maintain specific levels. Select Keep All.
- In the Tree View, toggle the visibility of the Surface node.
- To remove the pipe where the pond is to be located, in the model, with the Select tool active, click pipe 015.
- Press DELETE to delete the pipe.
- To import the CAD drawing of the pond, in the Tree View, right-click the CAD Data node and select Import Data.
- In the Load CAD Wizard, click Select.
- Select the file pond outline.dwg and open it.
- In the Load CAD Wizard, click Next. Note that the imported data includes multiple layers.
The Load CAD Wizard showing a preview of the pond outline as it will appear in the InfoDrainage model once it is imported, and the Finish button called out.
- Click Finish.
- On the ribbon, click the Plan tab and select Snap mode to enable it.
- In the Toolbox, expand the Stormwater Controls node to see a list of control systems.
- Click and drag the Pond option into the Plan View and drop it into the polygon representing the pond outline.
- Click each of the polygon’s vertices, then right-click anywhere inside the polygon to finish it.
- In the model, double-click the Pond icon to view its attributes in the Pond dialog box.
- In the Pond dialog box, set the pond’s Exceedance level to 32.309 (the Upstream Cover Elevation from step 2.)
- Set the Freeboard to 200 mm.
- Toggle ON the Depth field.
- Enter a Base Level (Elevation) of 30.434.
- In the Depth (m) column, enter a depth of 1.875 (the pond’s exceedance level minus its base level) into the second row, and press ENTER.
- Copy and paste the Area value of 449.43 from the first row into the second row and press ENTER.
- Open the Sizing Calculator.
- Expand the Method drop-down and click Side Slope.
- Enter a Side Slope value of 4.
- In the Maintain drop-down, ensure Top Area is selected.
- Click OK to close the Sizing Calculator.
- Click OK to close the Pond dialog box.
The pond updates in the Plan View to include a dashed line that represents its base area.
- Double-click the Pond icon to reopen the Pond dialog box.
- Click the Advanced tab.
- Enter a Manning’s n value of 0.030.
- Click OK to close the Pond dialog box.