Laserfiche WebLink
<br />Approach: <br /> <br />1l,l.Data Development The CRDSS database contains the historic period of record for <br />streamflow, diversion. evaporation, temperature. and precipitation data that are required for this <br />study, Unfortunately, some reservoir end-of-month content data may not be digitized for the <br />period of record and most diversion data is only digitized from 1975 forward. In this subtask, <br />missing reservoir end-of-month content data will be collected and missing diversion data <br />estimated for the selected study period prior to 1975. The existing CRDSS database will be <br />reviewed for reservoir end-of-month content data for the 20+/- reservoirs explicitly modeled in <br />Phase IIIa. Missing, non digitized reservoir end-of-month content data will be obtained from <br />published reports or owners and digitized in a format suitable for inclusion into the CRDSS <br />database by the State or other contractor. <br /> <br />Historic non digitized diversion data prior to 1975 will be identified from the CRDSS database. <br />For budgeting purposes it is assumed digitizing and verifying available diversion records prior <br />to 1975 is not practical. Rather missing data will be estimated for each of the 5 CRDSS Water <br />Resource Planning models by developing a simple program and input data which performs the <br />following: <br /> <br />· Reads the historic diversion data tIles developed for StateMod in Phase IIIa <br />· Reads a file which contains: (l) An average, wet or dry runofftype year indicator <br />for each year prior to 1975 in the study period based on a representative streamflow <br />gage in each basin. (2) Up to 5 sets of representative diversion years which <br />correspond to a typical wet, dry or average year in that basin. The first set of <br />representative diversion years will be the default applied to most structures. The <br />remaining 4 will be available for structures that require special treatment. (3) A <br />listing of structures that use the non default representative diversion year data. <br />. Estimates diversions for the selected study period prior to 1975 based the type of <br />runoff year (wet, dry, or average), Include a method to account for structures which <br />are known to have not diverted prior to 1975. <br /> <br />1l.2.Develop Natural Flows In this sub task natural flows will be developed at all stream gages <br />currently contained in the Phase IIIa Water Resource Planning models (approximately 180 <br />gages), Natural flows will be developed by executing the appropriate CRDSS Data <br />Management Interfaces in order to develop the data required to operate the baseflow component <br />of StateMod, Key input to this process will include: gaged streamflows, historic or estimated <br />diversions, historic or estimated reservoir end-of-month contents, and Phase IIIa diversion <br />efficiency and return flow properties (timing and location). If necessary, the State will be <br />responsible for performing any upgrades to the StateMod baseflow component to allow missing <br />streamflow data to be supplied as input and appropriately flagged on output. Also, the State will <br />be responsible for any unique formatting of the natural flow results by StateMod that may be <br />required for the historic data extension or stochastic data development models. <br /> <br />11.3.Historic Data Extension In this subtask. historic natural streamflow data gaps will be filled <br />and verified for use by the CRDSS Water Resource Planning Models. It is expected to be <br />accomplished by applying or enhancing an existing program that will: <br /> <br />· Read all historic streamt10ws selected for use in a basin or basins. <br /> <br />C :Iw\crdss\scopelboy IIIblcrdss3 .doc <br /> <br />0758 <br /> <br />5/30/97 - Page 17 <br />