Record Details
page 3-109
Digital Collections at BYU
| Field | Value |
|---|---|
| Title | page 3-109 Diamond Fork System Final Supplement to the Final Environmental Impact Statement, page 3-109 |
| Coverage | Electronic reproduction; |
| Format | 3-109 text/PDF |
| Rights | Brigham Young University; http://lib.byu.edu/about/copyright/generic.php Public Domain Public |
| Language | English; eng; en |
| Relation | Central Utah Project; Western Waters Digital Library; special status species channel versus an immediate reaction to daily variation monthly averages for baseline and proposed flows were used in the analysis it is also assumed that the any chang change 1 I in n flow due to tv thee thep the I 1 proposed r action would take place immediately while a gradual change in flow may be better for the ute ladies tresses to adapt migrate and colonize a onetime one time change in flow would undoubtedly open up new habitat that may be suitable for ute ladies tresses this analysis does not take into consideration any positive effects on the species that may offset the significance of the negative effects predicted by the hydrologic engineering center river analysis system model HECRAS HEC RAS see section 3761.2 37612 below the number of individuals per colony was estimated through a labor intensive survey of all potential habitat in the project area only flowering individuals were identified and included in the counts since vegetative individuals could only be identified through an inch by inch survey of all habitat this assumes a relatively constant relationship between flowering individuals and total number of individuals at any one colony or throughout the survey area individuals may not flower or even show aboveground above ground vegetative parts every year therefore the maximum number of flowering individuals identified within a colony boundary in any one survey year was used to characterize the potential effect on a particular colony the analysis then assumed that if a large number of flowering plants were identified in any one year at least that number remains present at that location even if fewer were identified in previous or subsequent years this is most likely a conservative assumption since it also may reflect a change in habitat conditions that may no longer be able to support ute ladies tresses it also was assumed that if even one flowering individual was identified at a location the entire similar surface point bar flood plain etc was potential habitat for that colony habitat acreage was defined as all the area within a single geomorphic surface similar to the area in which one or more flowering individuals of ute ladies tresses were identified therefore if the one plant was growing in a microhabitat micro habitat that was unique on this geomorphic surface the acreage assigned to this colony as potential habitat would have been greatly overestimated 3761.2 37612 37612 effect topic analysis methods ute ladies tresses A number of methods were presented in the 1999 completion of the diamond fork system biological assessment the most comprehensive method used which is presented here was the HECRAS HEC RAS analysis in the fall of 1998 a field team consisting of an ecologist and surveyor flagged select locations of the 60 ULT colonies along diamond fork creek and 10 along spanish fork river the team targeted 32 of the 60 colonies in diamond fork canyon and two of the 10 in spanish fork canyon for a total of 34 colonycross section surveys the surveyor collected topographic data ie a mean elevation of the colonyhabitat colony habitat and micro topographic changes within a colonyhabitat colony habitat and stream channel needed to generate several flow change scenarios using the HECRAS HEC RAS model hydrologic engineering center 1989 results of this modeling were used to predict water surface elevations from predicted flow scenarios and to correlate them with mean colony elevations baseline and proposed flows in cubic feet per second were used as input flows in the HECRAS HEC RAS modeling program and water surface elevations for these two types of flows were developed at each of the 34 colony cross sections as outputs the model also predicts the percentage of time a particular elevation at a colony would be inundate inundated cL four relative elevations of concern were identified at the cross sections for each of the 34 colonies mean surface elevation 6 below mean surface elevation 12 below mean surface elevation and 18 below mean surface elevation the HECRAS HEC RAS then calculated the percentage of time that each of these elevations was exceeded for each cross section this analysis was performed for both baseline and proposed flows differences in these percentages for baseline flows under the proposed action were examined for each cross section and for the average flows in the growing season april through october 3109 3 109 diamond fork system FSFEIS FS FEIS |
| Identifier | http://cdm15999.contentdm.oclc.org/cdm/ref/collection/WesternWatersProject/id/10338 |
