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verticals are typically used; whereas, the transect used for the dis- charge measurement should employ 20-30 verticals. In all cases, the velocity to be measured is the mean column velocity at the vertical. Velocity measurement techniques and rules governing measurement of mean column velocity may be found in Appendix B. Measurement of the velocity distribution is usually the most time consuming portion of the data collection procedure. Therefore, it is strongly recommended that current meters be provided for more than one member of the field team. Ideally, each member of the team should be outfitted with a. meter, and should know how to use it. The cost of additional equipment is minimal compared to the savings in time and manpower afforded by extra current meters. SEQUENCING STUDY AREA SETUP AND DATA COLLECTION Certain activities must be completed in study area setup before data collection can proceed. Additionally, certain types of data are closely related (such as stage and discharge) and it is advisable to measure these parameters as concurrently as possible. Therefore, the following sequence is suggested for establishing the study area and collecting the data. Step 1. Locate cross sections. Step 2. Establish benchmark and permanent reference points (headstakes) ?-' for each cross section.. Take.photographs as required. Step 3. Measure: distance between transects and assign stationing or station index. Step 4. Survey headstake elevations in reference to benchmark. Check for closure (Appendix A). Step 5. Survey water surface elevations at each transect. Step 6. Measure discharge at selected transect. Stet 7_ Measure velocity distribution at remaining transects Step 8. Measure cross section profile. If sounding is used to measure the profile, steps 7 and 8 may be combined. Also, if sounding is used, be sure to survey the portion of the profile between the headstake and water's edge. Describe substrate. Step 9. Recheck water surface elevations. If significantly different, redo Step 6. Step 10: Review field notes before leaving site. Co