Rainfall & Water Level - Flood Alert SystemProject Overview
In an effort to catch and hold floodwaters in the Plum Creek Watershed in Lockhart, Texas, a system of lakes, ponds and spillways was built by the Soil Conservation Service beginning in the 1950's. The system allows water to be released at an engineered rate, minimizing damage from heavy rains.
Plum Creek Conservation District (PCCD) monitors, maintains and improves this system to ensure that it works properly, maintaining 28 flood control structures and managing underground water resources in parts of both Hays and Caldwell Counties.
PCCD's mission is to develop and implement water conservation and management strategies to protect, conserve, and prevent waste of the groundwater resources in the District for the benefit of the citizens, economy and environment of the District.
One of the district's most recent water conservation and management strategy was to implement a real-time rainfall and water level monitoring network at 3 of the 28 flood control structures. NexSens Technology was asked to provide the equipment and services to install and setup this real-time network.
System Description
To monitor water level, PCCD project members chose the OTT PS1 pressure transducer. This low maintenance sensor provides water level measurements as accurate as 0.05%. Inside the versatile probe, a piezo-resistive pressure sensor linked to a microprocessor handles a wide variety of tasks involving signal processing and calculation.
The PS1 measures the combined pressure exerted on it by the atmosphere and the head of water above it. The internal firmware corrects for the influence of the temperature on the measuring cell, the effect of gravity, and even takes into account changes in the density of the water.
Rainfall measurements are obtained using the RM Young tipping bucket rain gauge. This highly accurate sensor uses a proven tipping bucket mechanism for simple and effective rainfall measurements. The bucket geometry and material of the RM Young rain gauge are specially selected for maximum water release, thereby reducing contamination and errors.
At user-defined intervals, the NexSens 3100-iSIC data logger with cellular telemetry sends the collected environmental data to the District's office PC running iChart software. The real-time monitoring system has ability to send various forms of alarms to PCCD staff members, making them aware of rainfall and flood events within the watershed.
By simultaneously measuring rainfall and water level, PCCD staff can effectively correlate changes in water level to the amount of precipitation produced by rainfall events in the watershed. Both NexSens iChart software and WQData web datacenter provide powerful data analysis and correlation capabilities to meet these tasks. 
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