Understanding SuDS design

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at times you may need to incorporate sustainable

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drainage systems or suds into a water drainage model

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When properly designed and placed

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suds can reduce flooding and improve water quality by reducing both flow

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rates and the amount of pollution carried to downstream water courses.

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For this exercise,

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it is useful to see how suds would fit into an existing drainage model,

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complete with pipes, a pond and a discharge control point,

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Assume an outflow or discharge rate of 16.1 L/s.

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Your goal is to place suds features in the catchment

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to control flow rates with the intention of being able to reduce the size of the pond

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to do this,

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you can use the deluge analysis features in info drainage to

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determine the location of low spots where water will naturally accumulate.

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Each

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structure will store water and include a flow limitation device

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to decrease the flow rates downstream

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so that the pond size can be reduced.

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In this example, there are some unknown variables,

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including the storage volumes of the suds features

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and the past forward rates downstream of each.

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However,

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for now assume that their storage volumes are fixed so that

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you can reduce the past forward rates as much as possible.

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This allows you to reduce the size of the pond.

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Start by creating a new phase,

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right click the pond design phase in the tree view,

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then select duplicate phase,

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click the lightbulb icon next to the original pond design phase to switch it off.

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Also click the green go button to stop further analysis on it,

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Then right click the new pond design one and select rename phase.

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Enter the name

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design

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and then press enter

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next.

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You need to import a background cat image to show the location of two suds structures

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in the tree view.

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Right click the cad data node

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and select import data to open the load cad wizard,

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click select and navigate to the info drainage, introduction folder

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data sub folder.

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Then select suds outlines

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and click open.

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Click next in the load cad wizard.

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On the select layer page you can see a preview of the many layers and

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labels included in this data but for this exercise you will only use one,

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click the select all

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and then drag the scroll bar to find the I. D. Underscore stormwater control layer,

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click the checkbox to enable it.

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You will see the preview area update to reflect the change,

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click finish

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in the plan view,

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you can now see the imported outlines of a Swail and permeable pavement area

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in the tree view. Deselect the checkbox next to inflows

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now that you can see how suds would fit into this existing drainage model.

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Your next step is to design these suds features