Current through Bulletin 2024-20, October 15, 2024
Section R655-12-4C - Instrumentation Monitoring and ReportingThe following monitoring and reporting requirements are applicable to all instrumented dams under normal, long term operating conditions, unless otherwise approved by the State Engineer. Under unusual conditions, the State Engineer may require additional criteria. Instrumentation requirements for new dams should be outlined in the Initial Filling Plan as per R655-12-3A. The type of instrumentation required is presented in R655-11-10.
1. Seepage in the vicinity of any dam shall be monitored, typically including lateral extent, turbidity and flow rate. Collection in a properly designed drainage system as outlined in R655-11-6E may be required.2. All piezometers and drains shall be monitored at least monthly when the reservoir exceeds 50% of the hydraulic height. Where reservoir elevations vary substantially over an irrigation season, readings shall be obtained on a weekly basis when the reservoir exceeds 90% of the hydraulic height. Readings can return to a monthly frequency four weeks after the reservoir level peaks, provided measurements are stable and within anticipated ranges. In all cases, instrumentation should be monitored at the beginning of the reservoir filling season, at the peak reservoir elevation, and at the maximum reservoir drawdown.3. The elevation of the reservoir shall be recorded at the time of all readings as described in 2. above.4. All dam instrumentation (including piezometers, drains, reservoir gage, survey monuments, and any other dam instrumentation) shall be monitored immediately following an earthquake where ground motions are felt in the area or the owner is informed of seismic activity in the vicinity. Results of the inspection and instrumentation readings should be immediately sent to the State Engineer.5. Copies of all instrumentation monitoring data should be forwarded to the State Engineer, on a monthly basis, following collection of the data. It is the responsibility of those obtaining the data to know if readings are within normal historical and/or design operating parameters. Emergency conditions should be assumed if readings exceed normal historical and/or design operating parameters and immediate notification of the State Engineer is required.6. All instrumentation shall be documented by plotting locations on a plan view of the dam and by assigning a unique, identifiable name. A table for all instruments which provides base line data shall also be prepared. Piezometer data should include the name, location, monitoring location (e.g., zone 1, zone 2, foundation), top elevation, total depth, and depth of porous interval. Drain data should include the name, location, collection interval, and flow rate monitoring methods. Survey monuments should include the name, location, and vertical and horizontal coordinates. The reservoir storage gage should be marked in at least one foot intervals and an elevation datum provided that is consistent with all other dam instrumentation.7. The data required for any other dam instrumentation (inclinometers, temperature probes, chemical composition), will depend on the type and purpose of the instrumentation.Utah Admin. Code R655-12-4C
Amended by Utah State Bulletin Number 2016-8, effective 3/24/2016