Division 1 Annual Report 1999 - Laserfiche WebLink

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Bureau of Reclamation, and dams regulated by the Federal Energy Regulatory Comrtnission(FERC). Due to some seepage concems being studied by the USBR at Horsetooth Dam, Mike Cola has continued to remain involved in the analysis and in spection process at that structure. Hvdro_qraphv W ater Supply for the South Platte River and its tributaries for the 1999 water year has continued to be abundant A comparison of historic average and 1999 total flows for the South Platte at Kersey and South Platte at Julesburg gives a good indication of the kind of year we had in 1999. South Platte at Kersey: Historic average flow (1976-1998) 910,O00 AF. 1999 Water year flow 1,343,000 AF. South Platte at Julesburg: Historic average flow (19o2-1s98) 402300 AF. 1999 Water Year flow 1,004,000 AF High flows have continued to alter channel geometries. Our hydrographers have been kept very busy making bridge measurements and developing new rating tables. In the past 2 years, 32 new rating tables have been developed for state-operated open channel gages on all the major tributaries and along the main stem of the South Plate River to the Nebraska state line. _ Our experience with flood level flows in late April and eady May focused our thinking on ways to provide better information during these critical periods. Some the findings of this experience are as follows: Extra visits we made to checlk gages were invaluable. We were able to fix operational problems-cloggecl inlets, recorder hang-ups, etc.-- that sometimes accompany rapid rises in stage. 2. Auxiliary stilling welis attached to bridges at manometer gages were an excellent investment. When water reached a bridge well, we would switch reporting to our secondary satellite encoder and avoid the problems often seen using manometers to record high flows. We plan two more bridge stilling well installations in the future. 3. Canal gages with secondary reporting on the spill over the diversion stnacture were good for tracking high flows. Administrative gages such as Cache La Poudre River at Greeley proved to be less useful, due to instabilities in the stage-discharge relationship. A site with an artificial control, reporting stage-only, could give more useful flood information than an administrative gage where bridge measurements were made. 4. Hydrographer communications from the field allowed office engineers to respond more effectively to inquiries about flood conditions. As a result, hydrographers were issued digital cell phones to maintain coordination and communication during critical events. Stream flow data gathered at gaging stations is the basic information used by water administrators and water users to determine the available water supply within the division. The Satellite Monitoring System is currently in transition to an intemet accessible database. A new "Water Talk" system is also being developed to allow the public and Water Commissioners to continue to atcess stream flow data by telephone. A new program for computation of hydrologic records is being developed at the same time. Division One took a lead role in 1999 in cooperative efforts with the USGS. An agreement was reached with the USGS data chiefs' committee to discontinue USGS publication of 11 Division One records, including all transmountain records. In tum, Division One will publish (in the DWR "Stream Flow Data for Colorado") a special 4