Laserfiche WebLink
performance and accuracy of the structure. It is the responsibility of the <br />structure's owner to maintain the structure in an operational manner. All <br />structures should be installed and maintained in a suitable fashion to <br />ensure free flow conditions per design considerations of the <br />measurement structure type. A synopsis of design and operational <br />considerations for typical measurement structures such as; weirs, <br />Parshall flumes and long throated flumes can be found in the United <br />States Bureau of Reclamation Water Measurement Manual 3rd Edition <br />available at: http://www.usbr.gov/pmts/hydraulics lab/pubs/wmm/. <br />c. Accurate instrument calibration is essential. Errors due to inaccurate <br />instrument calibration and maintenance practices may results in the <br />Water Commissioner giving no credit for waters delivered. Therefore the <br />following field practices should be implemented to ensure accurate <br />operation and calibration of the instrument. <br />i. A stilling well shall be cleared of accumulated sediment prior to <br />use and through the period of use, as needed. <br />Sediment will accumulate in the stilling well during its <br />operational period. When the structure is dewatered, the <br />instrument's float can "beach" on the accumulated <br />sediment thereby presenting erroneous stage and <br />computed discharges. <br />ii. Stilling wells shall be inspected for accumulated sediment during <br />periods of inactivity or low flow and cleared of any accumulated <br />sediment; and the inlet tubes to the stilling well shall also be <br />inspected and cleared of any obstructions. <br />iii. Site visits shall be made on a weekly, if not more frequently, as is <br />required to ensure instrument calibration against the base gage. <br />4. Instrument calibration corrections greater than ± 0.02 feet shall be corrected and <br />noted on a tabular log noting the date, time and magnitude of correction made to <br />the instrument. The log shall be kept and made available to the Water <br />Commissioner at the Augmentation Station. If the structure's owner is <br />unfamiliar with making instrument calibration corrections, then the Water <br />Commissioner shall be contacted to approve the correction methodology, <br />since there are several acceptable methods; and if necessary, provide <br />guidance with regard to performing the calculations. <br />5. Accounting MUST be performed on a daily basis and reports MUST be submitted <br />to the Water Commissioner and div1accounting@state.co.us at least monthly <br />and within 30 days of the end of the month for the month the accounting is being <br />made, or more frequently as required by the Water Commissioner. Accounting <br />submitted for Augmentation Stations shall include: <br />Aug Station Protocol <br />Effective May 12, 2011 <br />