When the well is dry,
we know the worth of water
Benjamin Franklin
Broward County, Florida has made a commitment to sustainability and currently has 4 County buildings that have been built to USGBC LEED standards. As part of this initiative, in October 2008 a County “Green Team” took its first steps toward what eventually would prepare the Convention Center for USGBC LEED certification for Existing Buildings: Operations & Management (EBOM). By 2009, the Center had a plan in place and was ready to move forward with LEED certification. An existing building retrofit to LEED standards is generally more problematic than for new construction which can incorporate standards from the ground up. This retrofit included countless items from cleaning products, lighting conversions, low flow toilets, faucets and dishwashers, cooling and heating systems as well as a complete exterior landscape and irrigation replacement (landscape and irrigation were approximately 20 years old). The resulting Florida-friendly landscape is water-wise and drought tolerant. It uses native and adaptive plants and trees that thrive in our South Florida climate while requiring less water than other plants to do so. Minimizing the use of turf was also very helpful to achieve the water savings required for LEED standards.
Masuen Consulting Masuen Consulting was hired to design the irrigation system to provide > 50% water savings as well as provide construction observation and GPS as-builting services. Masuen Consulting worked closely with the owners and landscape architect to design a complete irrigation and control system capable of efficiently providing water to the new plantings based on hydrozones. The system featured many elements/products that allowed this including drip tubing, turf rotaries, pressure regulation, flow sensing, soil moisture sensing, and a monitored central control system.
The project was well-received by all parties including the TPIE (Tropical Plant Industry Exhibition) which attracts a national attendance each year, and was held several months after the completion of the project. As of February 2012, the project was awaiting notification of both a local beautification award, as well as a Silver certification for LEED EBOM, quite an achievement for a 600,000 SF public facility!
Statistics:
The irrigation system was designed with drip tubing (90% efficient) in medians and pedestrian plaza planters. Turf rotaries (80% efficient) were used in all other applications. Bubblers (90% efficient) were used for all trees. Head-to-head layout was provided at 90% of the anticipated radius, enabling true head-to-head coverage even with the light breeze that is normal to the area. Zoning was very specific to match the plant hydrozones, as well as microclimates such as significant shade or no exposure to rainfall. Soil moisture sensors were placed in each typical hydrozone. These sensors provide soil moisture content directly to the controller. The controller has a logarithmic engine that considers the soil moisture content and calculates run times for each zone accordingly. A flow sensor identifies real-time flow conditions, and this information is verified against expected flows. A master valve allows the controller to automatically shut down the system if, during an irrigation cycle, the flow exceeds the required amount, or if flow occurs outside an irrigation event. The controller was provided with internet connectivity and is monitored by Masuen Consulting each day. Calculations in design suggested a 65% water savings was realistic. In February 2012, usage data is being analyzed and compiled for verification of this goal.
Ultimately, the client has been extremely pleased with the concepts Masuen Consulting recommended and designed, the system and the operational capabilities provided and the overall success of the project. Mark Gatley, the General Manager of SMG/Broward County Convention Center, has this to say about our involvement:
"Masuen Consulting's involvement in the landscape and irrigation project at BCCC was extremely valuable. As a result of their expertise, we were able to achieve the LEED credit for Water Efficient Landscaping as well as an annual reduction of water used for irrigation of approximately 5.5 million gallons of water."