Improve rainfall measurement network at Ventura County Public Works Department

The challenge

We were losing a lot of rainfall data due to several critical issues: Clogging: the funnels on our previous rain gauges would clog due to bird droppings compromising the ability of the gauge to deliver reliable data. An inferior tipping mechanism (pivots) also compromised the data. Calibration: prior to the widespread adoption of the TB3 in 2005, we were not only losing data, we were losing money due to having to fix sites and calibrate constantly. After careful consideration, we decided on the TB3 due to its features and reliability which were key in resolving the customer’s data loss issues.

• The TB3 incorporates a stainless steel finger filter that substantially reduces clogging
• Superior tipping bucket mechanism that uses low wear/low friction sapphire pivots.
• TB3 incorporates a flow control siphon for improved accuracy across a wide range of rainfall intensities.

The solution

Ventura County Public Works Department selected the TB3 due to its unique design, robust construction, anti-clogging finger filter, sapphire bearings, flow control (siphon) mechanism and long term stable calibration. They currently have a network of 75 TB3 Tipping Bucket Rain Gauges.

Customer voice: After careful consideration and some convincing, in 2005 we began to replace existing gauges with the TB3 Tipping Bucket Rain gauge. Once we knew what we had in our hands….there was no more convincing needed.

The TB3 is the backbone of our Rainfall Monitoring network and not only do we rely on the data but other agencies nearby including Los Angeles, Santa Barbara and San Luis Obispo counties also observe our data and benefit thereby. In fact during the devastating 2018 Montecito mudslide in nearby Santa Barbara county it was the data provided by Ventura County’s TB3 rain gauge network that many agencies looked to. The Ventura County Public Works Department intends to maintain the model TB3 Tipping Bucket Rain Gauge as their frontline instrument.

The benefits

TB3 resolved data loss issues

Prior to widespread adoption of the TB3 tipping bucket rain gauge, data loss was a significant issue for us due to clogging, inferior tipping bucket mechanism and gauges repeatedly going out of calibration, requiring excessive site visits and man hours to fix issues. Since the incorporation of the TB3 we have experienced substantial improvement in data quantity and quality.

Minimum 20% reduction (savings) in man hours

Reduction in man hours and our overall costs to maintain our gauge network was key. Resolving the problematic tipping bucket mechanism issue, clogging issue and repeated need for calibration was a game changer for us. Resolving these issues has led to a substantial reduction in site visits to repair and maintain calibration, freeing up our field technicians to focus on more pressing tasks rather than repairing existing sites This measurable reduction in site visits is due to TB3’s long term, stable calibration.

Dual Reed Switch/ML1 mini logger

After some analysis it was determined that a back up logging capability needed to be implemented to prevent data loss. Prior to the implementation of the TB3 tipping bucket rain gauge this was not possible.

With the TB3s dual reed switch feature we could connect one reed switch output to the KISTERS (formerly HyQuest Solutions) ML1 mini logger installed in the rain gauge and the other to our flood warning transmitter. The ML1 was key in allowing us to do this. Every single TB3 in our Rainfall Monitoring network has an ML1 mini logger attached. We use the ML1 mini logger as the official record on every site due to instanteous time stamp on every tip. This not only gives us back up data, the ML1’s battery lasts a whole year, in back country sites this is critical.