Blake Anderson is the harbormaster at the Santa Cruz Harbor in California. As harbormaster he oversees all the operations of the harbor, harbor patrol staff, which includes search and rescue, law enforcement and public safety. He also oversees administration of about 1000 boat slips and day to day operations of the harbor. 6 years ago, Blake was faced with the challenge of rapidly mapping the constant shifting sand shoals in the harbor and turned his attention to BioBase as a potentially rapid mapping system
Earlier this year, Senior Biologist Scott Bryan from the Central Arizona Project (CAP) blogged about how the CAP is using BioBase to manage sedimentation in Arizona’s lifeblood 336-mile aqueduct. Since then, CAP GIS Wizard Glenn Emanuel has worked some amazing magic on the BioBase grid exports using Spatial and 3D Analyst Extensions for ArcGIS (Figure 1).
The data and images allow CAP to make informed decisions regarding the efficiency of sediment removal operations. In addition, ArcScene was used to produce a 3D scene of the forebay (Figure 2), which can then be animated with a video fly-through.
Any user of BioBase properly equipped with the proper third party GIS software can create these amazing map products that are more than just pretty pictures. They create a real-life, tangible perspective of aquatic resource conditions that BioBase users are interested in managing, protecting, and restoring.
The Central Arizona Project (CAP) is a multipurpose water resource development and management project that provides irrigation, municipal and industrial water to much of Arizona. The primary means of water conveyance is a 336-mile concrete-lined aqueduct that transports water from the Colorado River, on Arizona’s western border, across the State to Phoenix, and then southward to the aqueduct terminus near Tucson. Each year, over 1.5 million acre-feet of water is delivered to our customers.
Since its completion in 1993, the aqueduct system has experienced increasingly severe sedimentation that creates problems within the pumping plants and in the aqueduct itself. Because the sediments can decrease the flow capacity of the aqueduct, cause damage to pumps and internal systems, and restrict flow through critical filtration units, it is imperative that dredging operations occur periodically.
|CAP forebay dredging in 2009|
In the past, CAP performed intensive sonar based sediment studies to determine bathymetry and the amount of deposition in the forebay of each of the 13 pumping plants. The surveys show when and where dredging operations should occur. These surveys were contracted to outside companies with costs ranging from $40,000 to $120,000 annually.
In 2012, CAP began to use the sonar technology provided by BioBase to conduct its own bathymetry surveys in the pumping plant forebays. Water depths are compared to historical baseline surveys and the volume of sediment in each forebay can easily be calculated. Annual surveys allow us to compare sedimentation from year-to-year to determine loading rates and critical areas to target sediment removal. Surveys of all 13 forebays can now be accomplished in three days rather than six months, and when compared to the expensive surveys from the past, are equally as accurate.
|Blue-scale bathymetric map of a CAP forebay. The light blue contours show an area that is extremely shallow and is in need of sediment removal.|
|Example transect design and resultant bathymetric map coupled with the sonar log viewer. Notice the detailed image of the forebay’s trash racks produced by Lowrance HDS DownScan|
Scott Bryan is the Senior Biologist for Central Arizona Project (CAP). After receiving an M.S. in Fisheries Management at South Dakota State University, Scott worked as a research biologist for Arizona Game and Fish for 10 years, then specialized in lake and stream management for seven years at a private consulting firm in Albuquerque. Scott’s current position at CAP includes a broad scope of work, including aquatic and terrestrial vegetation control, fisheries and wildlife management, invasive species research, and water quality monitoring.