Conducting a Quick Storage Estimate

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once the basic shape of a pond has been defined,

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the next task is to conduct a quick storage

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estimate to obtain an approximate value for the volume.

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This is then refined by simulating the network with a series of design storms

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with a model open in the plan view in the results

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tab click in flow summary and scroll to the bottom.

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Note that the area to be analyzed is 2.5-1 hectares.

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Keep that last value in mind as it will play

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a critical role in setting the size of the pond.

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Close the dialog

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in the plan view double click the pond icon and open the sizing calculator.

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Set the method. Drop down to quick storage estimate

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and set the design up to drop down to free board.

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You have the option to manually enter a

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volume but instead click the calculator icon.

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This opens a dialogue where you can input several values

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set,

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the input type drop down to user input and the area

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field to 2.5 to the 2.5 to 1 hectares being analyzed,

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rounded down

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In the volumetric runoff coefficient field, enter a value of 0.750.

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This means that during a rainfall event,

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into the drainage system and eventually into the pond,

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Enter a discharge rate of 16.1 which was

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calculated earlier from the Green Field Runoff.

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You can also enter a value for the ponds infiltration rate

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or how much water will go into the ground through the walls of the pond.

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In this case assume that the pond lining is Impenetrable

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and do not enter a value.

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The safety factor in this example is set to

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expand the drop down below it and set it too quick.

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Next

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make sure the srp wizard F S R option is enabled,

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click calculate to view the results.

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The quick storage estimate for this pond is somewhere in the range of 705 and 997 m3.

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Keep in mind these values are only estimates and

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should not be used for final design purposes.

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Click OK.

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The sizing calculator now displays a volume of 850.796 m3 which is

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the middle of the estimated volume range from the quick storage estimate.

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Keep in mind that a full simulation will be required to confirm

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the actual volume but this is a good approximation for now.

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Click OK

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notice that the ponds dimensions change slightly in the preview area of the pond.

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Dialogue

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click OK.

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In the plan view you can see the

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pond's appearance changed to reflect its new measurements.

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In this example, the pond displays a blue line,

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this is a layer of imported cad data that

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gave an outline of the pond's initial shape and size

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since it is no longer relevant,

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click the box next to the pond outline dot D W G node in the tree view to deactivate it