Overview

This case study examines the irrigation system implementation at Auburn University's Recreation and Wellness Center, focusing on how BaseStation 3200 technology solved complex water source management and flow control challenges. The project demonstrates automated cistern filling, multiple water source coordination, and high-volume irrigation management across both natural turf and synthetic playing surfaces.

Site Background

Auburn University Campus

Auburn University, located in Auburn, Alabama, opened in 1859 and serves over 25,000 undergraduate students on an 1,800-acre campus. The Recreation and Wellness Center represents a significant expansion of the university's intramural athletic facilities.

Recreation and Wellness Center Facilities

The project encompasses both existing and newly constructed athletic fields:

• Original intramural fields with natural turf (existing)
• New artificial turf softball fields
• New artificial turf football fields
• New artificial turf soccer fields
• Natural turf areas including two softball/baseball diamonds and soccer fields

The addition of synthetic turf fields significantly increased the facility's capacity to handle intramural activities, but also introduced unique irrigation requirements for cooling and rinsing the artificial surfaces.

Irrigation Requirements and Challenges

Artificial Turf Irrigation Demands

The synthetic turf fields require large Hunter in-ground turf rotors that consume approximately 250 gallons per minute. These high-volume irrigation heads serve two primary purposes: cooling down the artificial turf during hot weather and rinsing the surfaces. A 12-inch main line loops around the artificial fields to accommodate this high water demand.

Unlike natural turf irrigation, which follows regular schedules for plant growth, the synthetic field irrigation operates on an as-needed basis rather than a fixed schedule.

Water Supply Infrastructure

The site utilizes multiple water sources feeding a central storage system:

• Four wells scattered across the property with combined flow rates of approximately 80-85 gallons per minute (individual wells produce 10-25 gallons per minute)
• City water connection capable of 350-400 gallons per minute
• 64,000-gallon cistern that receives water from all sources
• Pump station with capacity up to 1,500 gallons per minute that draws from the cistern

While city water is available in Alabama at relatively low cost compared to other regions, well water remains the preferred and most economical source.

Critical Water Management Challenge

The project faced a significant water supply and storage challenge. With a pump station capable of 1,500 gallons per minute and a 64,000-gallon cistern, the system could theoretically empty the entire cistern in just 42 minutes of continuous operation. Furthermore, only the water above 35 inches in the cistern is usable, as water below that level sits beneath the suction line, effectively reducing available storage capacity.

Even when running all water sources simultaneously (80 gallons per minute from wells plus 300 gallons per minute from city water), the recovery time to refill the cistern would be approximately two and a half hours. This created a critical need for sophisticated flow management and water source coordination.

Why BaseStation 3200 Was Selected

The primary reason for selecting Baseline technology was to solve the flow management and water source management challenges. While other control systems such as PLCs or specialized pump station controllers could manage the wells, city water connection, and hydrometers, those solutions would require an additional investment of $10,000-$30,000 or more on top of the irrigation controller.

The BaseStation 3200 includes all necessary water source management, flow control, and automation capabilities built into the system, eliminating the need for separate control packages. This integration provides comprehensive automation at a lower total system cost.

Hardware Configuration

Primary Controller and Capacity

The system uses a BaseStation 3200 as the primary controller. The BaseStation 3200 can handle:

• Up to 200 zones
• Eight water sources
• Eight control points
• Eight main lines

The Auburn project utilizes 122 zones, leaving capacity for future expansion.

Substation Addition

The project includes a Baseline substation to extend the system's reach. The substation became necessary because the two-wire path exceeded the electrical specifications for a single controller. By splitting the system in half, the electrical load was divided between the BaseStation 3200 and the substation, keeping both within proper operating parameters.

The substation communicates wirelessly to the BaseStation 3200, allowing it to be placed at a strategic location on site. This wireless connection means the two-wire path originating from the substation starts at that device rather than running all the way back to the main controller, effectively creating two separate two-wire paths that are coordinated through the wireless connection.

The substation location utilized an existing station site where a 5200X controller had previously been installed. By adding the substation hardware at this location, the project avoided additional infrastructure costs.

Communication Architecture

The system employs two different communication methods working together through Baseline's IoT (Internet of Things) cloud networking:

• The BaseStation 3200 uses a cellular modem to communicate with BaseManager
• The substation connects via Ethernet
• Both devices communicate with Baseline's cloud server
• The server acts as a middle manager, allowing the BaseStation 3200 and substation to share data despite using different communication networks

This cloud networking capability represents a newer option that wasn't available in previous years. Rather than requiring the substation to communicate directly with the BaseStation 3200 on the same network, both devices communicate with the server independently, and the server coordinates data sharing between them.

Flow Monitoring and Control Points

The system includes eight flow meters (flow sensors) and eight master valves distributed throughout the irrigation system to measure and control water movement. Some of these flow meters and master valves are combined into hydrometers. These components can be configured together as control points.

The BaseStation 3200 supports up to eight control points, where each control point can include:

• A master valve
• A flow device
• A pressure component

The Auburn project currently uses the master valve and flow components at each control point. The system has capacity for eight additional pressure sensing devices if needed in the future.

Event BiCoders for Cistern Level Management

Four event switches (event biCoders) provide the critical automation for cistern level management. These devices interface with sensors in the cistern to trigger automated responses based on water levels.

The cistern contains a level transducer sensor installed by Watertronics (the pump station manufacturer). This sensor measures water pressure at the bottom of the cistern to determine the water level in inches. The sensor provides signals to both the Watertronics pump station controls and to Baseline's event biCoders.

The four event biCoders serve distinct functions:

• Well activation control: Turns wells on or off based on cistern level
• System shutdown protection: Stops all irrigation schedules (except well filling) if the cistern drops below a critical level, preventing the pump station from experiencing low-pressure shutdown that would require manual restart
• City water control: Manages city water supply as needed
• Overflow prevention: Stops filling operations before the cistern reaches maximum capacity to prevent overflow

This configuration was coordinated during the specification process with the irrigation designer, Bob Scott of ICS in Atlanta, Georgia, to ensure proper integration between the pump station controls and the Baseline irrigation system.

In current projects, Baseline's own pressure transducer biCoder could replace the third-party level sensor, allowing the system to directly measure and display cistern levels in inches through BaseManager. At the time of the Auburn project, this capability wasn't yet available, so the system uses simple open/closed signals from the Watertronics controls triggered by their level sensor.

Baseline Two-Wire Technology Advantage

The entire system relies on Baseline's two-wire technology, which provides two-way data communication between the controller and field devices. This is a critical differentiator from traditional irrigation control systems.

When Baseline refers to "two-wire technology," it means a data communication cable that can both send commands from the controller to field devices and receive information from field devices back to the controller in real time. This is fundamentally different from systems that simply turn valves on and off.

Real-time data communication is essential for the Auburn application. With the pump station capable of drawing 1,500 gallons per minute and the critical cistern level at 36 inches, the system could drop below the safe operating level in approximately three minutes without real-time monitoring and response. The two-wire system ensures immediate response to changing conditions, protecting the pump station from low-pressure shutdown situations.

Programming Solution Architecture

Core System Components

The programming solution utilizes three fundamental components that are core to Baseline systems:

Water Source: In this project, the pump station serves as the water source. While the wells, city water, and cistern are all part of the water supply chain, they feed the cistern, and the pump station draws from the cistern to supply the irrigation system. The BaseStation 3200 can handle up to eight different water sources, which could include multiple pump stations, water meters, or other supply points that directly feed main lines.

Control Points: These can include a master valve, a flow device, and a pressure component, either individually or in combination. The Auburn system uses master valves and flow components at its control points, with capacity for eight additional pressure devices. The system supports up to eight control points total.

Main Lines: These carry pressurized water from the water source out to the irrigation zones. The system can manage up to eight different main lines, each with its own flow limits and characteristics.

Automatic Cistern Filling Operation

The cistern filling operates as an on-demand, fully automatic system that functions independently of the irrigation schedules:

When the cistern level drops below a predetermined threshold, the event biCoders trigger the well pumps to begin filling. As the level continues to drop or if the wells cannot keep pace with demand, the city water supply activates as needed. The event switches use start and stop conditions to run the wells and city water rather than operating on fixed schedules or times.

If the cistern reaches a critically low level, the system executes a full stop of all irrigation to prevent the pump station from shutting down due to low pressure. Since the Auburn system has only one water source (the pump station), this stop condition halts all irrigation. If the system had alternate water sources configured, it could switch to backup supplies instead of stopping completely.

The filling schedules operate completely autonomously and do not adhere to rain shutoffs or other conditions that affect regular irrigation schedules. This separation ensures the cistern maintains adequate levels regardless of weather-based irrigation adjustments.

Main Line Configuration and Flow Limits

The system uses separate main lines with different flow characteristics to match the distinct irrigation requirements:

12-Inch Main Line (Main Line 1): This main line serves the large rotors on the synthetic turf fields. Because of the 12-inch pipe diameter and high-volume irrigation heads, this main line has very high flow limits set in the controller, potentially 800-1,000 gallons per minute or more before triggering a high-flow alarm.

4-Inch Main Line (Main Line 2): This smaller main line serves the landscape zones with natural turf and plantings. The flow limit for this main line is set much lower, perhaps around 300 gallons per minute, to match the capacity of the smaller pipe.

By programming different limits for different main lines, the system can detect problems specific to each portion of the irrigation system. If the 4-inch main line breaks, the system will detect the excessive flow on that main line and respond appropriately, while the 12-inch main line continues to operate normally within its higher flow parameters.

Concurrent Operation

The irrigation schedules for both main lines operate on traditional programming with start times, run times, and days of the week. These schedules run concurrently with the automatic cistern filling operation. The tank filling and the irrigation schedules function as two independent but coordinated systems, all managed within the single BaseStation 3200 controller without requiring additional control hardware or software.

System Benefits and Capabilities

Integrated Control Without Additional Hardware

All water source management, flow control, main line monitoring, and automated cistern filling capabilities are built into the BaseStation 3200 firmware. The only additional hardware required beyond standard irrigation components was the event biCoders to interface with the existing level sensors. No separate PLCs, pump controllers, or specialized automation systems were necessary.

Multiple Programming Approaches

The Baseline system offers flexibility in how the automation is configured. There is no single "correct" way to program the water source management and cistern filling. The system can be set up using water sources with start and stop conditions, or configured using programs with start conditions, or other approaches depending on site-specific needs and preferences.

Automated Valve Control and System Protection

By automating the water source switching and valve operations, the system prevents common problems that occur with manual valve systems:

• Eliminates the risk of pumps running against closed valves (deadheading), which can damage equipment
• Prevents accidentally pumping water back into the city supply due to incorrect valve positions
• Removes the need for personnel to manually open and close valves or restart equipment
• Provides fail-safe protection for the pump station by stopping irrigation before critical low-level conditions occur

Real-Time Monitoring and Response

The two-way communication capability allows the system to monitor conditions and respond in real time rather than waiting for scheduled check-ins or polling cycles. This immediate response is critical when dealing with high flow rates and limited storage capacity where conditions can change dramatically in minutes.

Room for Expansion

With 122 zones currently installed out of a 200-zone capacity, the system has significant room for future expansion. Additional pressure monitoring devices can be added to the existing control points, and the system can accommodate more zones, water sources, control points, or main lines as the facility's needs evolve.

Video Walkthrough

Video originally published January 2021.

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