Changes

</ol>

</ol>

<h4>Irrigation</h4>

<h4>Irrigation</h4>

<p>Regular irrigation has been shown to substantially reduce the stormwater capture benefit of an extensive green roof[http://ascelibrary.org/doi/abs/10.1061/(ASCE)HE.1943-5584.0001534]. However, due to their limited water retention capacity many green roofs are coupled with a cistern to capture the excess water. It then becomes desirable to use as much harvested water to regain the cistern capacity,  Green roofs can be irrigated to saturation daily throughout the growing season without damaging the vegetation. </p>  

<p>Regular irrigation has been shown to substantially reduce the stormwater capture benefit of an extensive green roof[http://ascelibrary.org/doi/abs/10.1061/(ASCE)HE.1943-5584.0001534]. One way to reduce the irrigation used on green roofs is through the use of electronic technologies. Responsive sensors that suppress irrigation after a rainstorm are routinely attached to green roofs to conserve water. Improvements can be made by instead using a 'soil' moisture sensor to trigger irrigation. State-of-the-art management systems now use predicted weather data to  prevent irrigation ahead of storm events[https://optirtc.com/products]. 

<p> Due to their limited water retention capacity, many green roofs are coupled with a cistern to capture the excess water. It then becomes desirable to use as much harvested water to regain the cistern capacity,  Green roofs can be irrigated to saturation daily throughout the growing season without damaging the vegetation. </p>  

<table class="table table-bordered table-hover">

<table class="table table-bordered table-hover">

<th class = "success"><td>Irrigation technology</td><td>Benefits</td><td>Disadvantages</td></th>

<tr class = "success"><td>Irrigation technology</td><td>Benefits</td><td>Disadvantages</td></tr>

<tr><td>Spray</td><td>Maximizes evaporation</td><td>Requires higher water quality standard</td></tr>

<tr><td>Spray</td><td>Maximizes evaporation</td><td>Requires higher water quality standard</td></tr>

<tr><td>Drip</td><td>Harvested rainwater is readily used without further treatment</td><td>Planting medium does not 'wick' water sideways readily, so can lead to localized dry areas</td></tr>

<tr><td>Drip</td><td>Harvested rainwater is readily used without further treatment</td><td>Planting medium does not 'wick' water sideways readily, so can lead to localized dry areas</td></tr>