The Urban Drainage and Flood Control District does not warrant the accuracy of the ALERT data provided by this website. The ALERT database contains some erroneous data. Therefore, the user of this data should not consider any of this data valid without further verification.

All ALERT gaging stations communicate data using 300-baud FM radio transmissions, which are rebroadcast by one or more radio repeaters. Radio interference is one common source of bad data. Wind, hail, snow, birds, insects, and lawn irrigation systems affect rain measurements. Human tampering is a problem at certain sites. Routine maintenance activities involve manual testing of rain gages, water level sensors, and other devices. Electronic switches on tipping-buckets occasionally malfunction causing false rain measurements. Meteorological data such as wind, temperature, and relative humidity may be affected by physical conditions surrounding the station (e.g. false temperature readings due to rising heat from nearby paved or other reflective surface, false RH values caused by irrigation systems or nearby standing water, false wind readings caused by nearby obstructions). Lightning can also cause false reports. Bogus data is sometimes difficult to recognize, even for experienced users.

Even if all ALERT gaging stations could work perfectly, base stations are another possible source of error. There are multiple ALERT base stations operating in the Denver/Boulder area that collect data independently. Consequently, some data inconsistencies between base stations should be expected. Each base station computer uses its internal clock to attach UTC (or GMT) date/time values to data reports received from the gages. This record is then stored in a database file and the computer displays information using local time (MDT or MST), unless otherwise specified. Computer clocks vary in accuracy and must be reset occasionally. Internal clock batteries eventually expire and must be replaced. When sensors in the field are electronically adjusted or replaced, the ALERT database record must also be re-calibrated. An uncalibrated record may be difficult to detect. Field maintenance reports, calibration notes, rating tables, alarm settings, and other written records are available for inspection at the District.

Due to the large number of ALERT stations reporting data, it is not practicable to manually correct all erroneous reports received by the base stations. Attempting to do so would require considerable effort and present yet another possible source for error. The District maintains electronic records of data collected by base stations located at the District's office. Individuals requesting information are provided with data from this site unless a known problem requires using an alternate site. Evaluation, interpretation, and verification of ALERT data are the responsibility of the user.

All ALERT data obtained via the Internet is accomplished through the ALERT Web Server. If you experience any problems using this system or have any questions concerning this Disclaimer, contact Kevin Stewart at the District.

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