One topic on discussion during the symposium I believe is in need of even more discussion is the implementation of a requirement to monitor the long-term performance of green roofs.
The need for annual green roof monitoring is essential. Too often we encounter failing green roofs. The green roof ecosystem is fragile, especially in its early establishment years, and can fail for many reasons. They can fail due to poor design, poor installation, wrong material choices or negligent maintenance, and none are mutually exclusive. The effect this has on the performance of a green roof is dramatic. A complete failure of a green roof system can occur rapidly and it is a huge liability, both economically and for safety reasons. Let us also not forget that a bad green roof is an image problem for all of us and reflects badly on the entire industry. Each green roof that fails to support its vegetation or leaks is one more stigma the entire industry has to overcome.
A mandatory green roof monitoring system, whether operated by a government agency or an independent 3rd party, would be able to identify failing green roofs and require whatever is necessary to restore the green roof to a proper level of performance. We believe any green roof that is supporting a healthy ecosystem, complete with year-round vegetation cover, is more likely than not properly functioning and meeting leading performance metrics.
Recently, buried within Maryland’s Stormwater Management – Watershed Protection and Restoration Program was a clause that requires annual monitoring of stormwater bmp’s:
(III) PROCEDURES FOR MONITORING AND
ANNUALLY VERIFYING THE EFFECTIVENESS OF THE ON–SITE SYSTEMS, FACILITIES, SERVICES, OR ACTIVITIES IN REDUCING THE QUANTITY OR IMPROVING THE QUALITY OF STORMWATER DISCHARGED FROM THE PROPERTY.
Striking ‘annually’ from the clause is disappointing and the legislators have essentially gutted this clause of its ability to secure long-term performance effectiveness. Once again we believe a mandatory monitoring system is essential and it is only a matter of time until one is implemented. Who will be the first?