Changes

Many studies show that LID practices help reduce peak flows during smaller, more frequent storms. They work by detaining runoff and releasing it slowly over time. However, larger events can overwhelm the capacity of LID practices. Once their storage capacity is full, the [[overflow]] rapidly discharges excess water into storm sewers, thus limiting their ability to mitigate large flood events. LID designed for flood control should integrate large active storage volumes to temporarily store stormwater and slowly release it to streams or downstream sewer systems. The mechanisms by which conventional wet ponds and hybrid stormwater infiltration trench/bioretention facility provide this temporary storage are shown in the figures on the right.

Many studies show that LID practices help reduce peak flows during smaller, more frequent storms. They work by detaining runoff and releasing it slowly over time. However, larger events can overwhelm the capacity of LID practices. Once their storage capacity is full, the [[overflow]] rapidly discharges excess water into storm sewers, thus limiting their ability to mitigate large flood events. LID designed for flood control should integrate large active storage volumes to temporarily store stormwater and slowly release it to streams or downstream sewer systems. The mechanisms by which conventional wet ponds and hybrid stormwater infiltration trench/bioretention facility provide this temporary storage are shown in the figures on the right.

When designing LID for flood control it is important to consider the need to not only provide extended detention storage but also a means for water to enter the storage reservoir quickly.  Incoming flows should also be pre-treated to avoid clogging of media and drainage pipes.  Such pre-treatment can be achieved through OGS, catchbasin inserts or high flow cobble inlets, among others.  The storage media in the LID facility should have a high void ratio to reduce the potential for clogging with fine sediment that may bypass the inlet pre-treatment controls.

When designing LID for flood control it is important to consider the need to not only provide extended detention storage but also a means for water to enter the storage reservoir quickly.  Incoming flows should also be pre-treated to avoid clogging of media and drainage pipes.  Such pre-treatment can be achieved through OGS, catchbasin inserts or high flow cobble inlets, among others.  The storage media in the LID facility should have a high void ratio to reduce the potential for clogging with fine sediment that may bypass the inlet pre-treatment controls.<br clear="all" />

 

[[File:Illicit-discharge.png|250px|thumb|left|Keeping inlets clear via pre-treatment and maintenance helps take advantage of the full storage capacity of the LID feature <ref>https://www.myclearwater.com/My-Government/0-City-Departments/Public-Works/Help-Keep-Clearwaters-Stormwater-Clean</ref>]]<br clear="all" />

==Literature Review==

==Literature Review==