The use of maintenance holes/vertical standpipes connected to the perforated pipe system are used for inspection and flushing, ensure couplings used for standpipe connections are 45° to facilitate pipe access by camera or cleaning equipment. (See below for example of couplings attaching to an underdrain pipe):
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The use of maintenance holes/vertical standpipes connected to the perforated pipe system are used for inspection and flushing, ensure couplings used for standpipe connections are 45° to facilitate pipe access by camera or cleaning equipment. (See to the right for example of couplings attaching to an underdrain pipe.
[[File:45 degs.PNG|thumb|400px]]
[[File:45 degs.PNG|thumb|400px]]
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===Conveyance and Overflow===
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Swales can be designed to be inline or offline from the drainage system. Inline swales accepts all flow from the drainage area and conveys large event flows through an overflow outlet. Overflow structures must be sized to safely convey large event flows out of the facility. Options include flat, dome or ditch inlet catch basins connected to a storm sewer.
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See: [[Overflow: Gallery]] for examples.
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===Monitoring Wells===
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A vertical standpipe consisting of an anchored 100 to 150 mm diameter pipe with perforations along the length within the reservoir, installed to the bottom of the facility, with a lockable cap. The well allows monitoring of inter-event drainage times with the use of a water level data logger sampler.