Changes

<p>To minimize erosion and maximize the functionality of the swale, sheet flow of surface water should be directed into the side of the BMP. [[Vegetated filter strips]] and shallow side slopes are ideal. Alternatively, a series of curb inlets can be employed, where each has some form of flow spreading incorporated.  Single point inflow can cause increased erosion and sedimentation which will damage vegetation and contribute to BMP failure. Again, flow spreading devices can mitigate these processes, where concentrated point inflow is required. </p>

<p>To minimize erosion and maximize the functionality of the swale, sheet flow of surface water should be directed into the side of the BMP. [[Vegetated filter strips]] and shallow side slopes are ideal. Alternatively, a series of curb inlets can be employed, where each has some form of flow spreading incorporated.  Single point inflow can cause increased erosion and sedimentation which will damage vegetation and contribute to BMP failure. Again, flow spreading devices can mitigate these processes, where concentrated point inflow is required. </p>

<h4>Underdrains</h4>

<h4>Underdrains</h4>

<ul>

<ul>

<li>Underdrains should be constructed from perforated plastic (PVC or HDPE, between 100 - 200 mm). The larger 200 mm diameter is recommended to address any concerns about freezing conditions.  </li>

<li>Underdrains should be constructed from perforated plastic (PVC or HDPE, between 100 - 200 mm). The larger 200 mm diameter is recommended to address any concerns about freezing conditions.  </li>

<li>The drain should be embedded into a coarse gravel layer, with a minimum of 100 mm aggregate below the pipe and 150 mm aggregate above. the pipe. To reduce the potential for sediment clogging the pipe, the gravel layer should be overlaid with a geotextile filter fabric. </li>

<li>The drain should be embedded into a coarse gravel layer, with a minimum of 100 mm aggregate below the pipe and 150 mm aggregate above. the pipe. To reduce the potential for sediment clogging the pipe, the gravel layer should be overlaid with a geotextile filter fabric. </li>

<li>A vertical standpipe connected to the underdrain can be used as a cleanout and as a monitoring well. </li>  

<li>A vertical standpipe connected to the underdrain can be used as a cleanout and as a monitoring well. </li>  

</ul></p> 

</ul>

 

<h4>Check dams</h4>

<h4>Check dams</h4>

<p>Check dams are a feature of enhanced swales. They promote infiltration and evaporation by promoting limited ponding.  

<p>Check dams are a feature of enhanced swales. They promote infiltration and evaporation by promoting limited ponding.  

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Check dams.png| Dam it

Check dams.png| Distance between dams determined by equaling the crest of each dam, with the elevation of the toe of the upstream dam. 

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