5. 



8. 



" eCtl r 0nS Ca " bE Placed ln a sJn * le riff le or a number of different 

 rif es Cross-sections should describe the typical riffle habitats 

 within the stream reach being studied. Other critical habitat tv 

 also be used, depending on your chosen method. ™ 



?h^ b t%east rl 3 ff i e d USl f ng LV Cr ° SS - SeC t±0nS - IC is -contended 

 that at least 3 and preferably 5 riffle cross-sections are used The 

 program accepts 1 to 10 cross-sections per study area. 



Ihe WETP model assumes that the water surface elevations at the water's 

 edge on the left bank (WEL) and right bank (WER) of a cros -section ar^ 

 always equal at a given flow. This is a valid assumption since the water 

 surface elevations at WEL and WFF. generally remain within 0. If t of each 

 other as the flow changes, provided the water surface eleva ions at WEL 

 and WER were matched when the cross-section was established Avoid 

 pacing cross-sections in areas where this assumption is like y to be 

 Isl n ^ ' Tf Ch T SharP bendS ? rlVPrS ^ mu]ti P^ channels con'tainin: 



Place the headstake marking each cross-section well up on the bank 



addition t M 6 alm ° St flUSh Wlth the gr ° Und and m - k -11 In 



addttion to marking the cross-section, the headstake is also your zero 



reference point for measuring horizontal distances across the 

 cross-section. Headstakes for all the cross-sections within a study area 

 should be located on the same bank. V 



Another stake is driven directly across from the headstake on the 

 opposite bank Place this stake so that the water surface elevations at 



withTn o"' ft ° f TM C 'V'" 18 ^ —-section are equal or SiUr 

 (w thin 0. 0J it). Ibis will require the use of a level and level rod 



1 stake is used to mark the cross-section on the bank opposite the 

 headstake and also to attach the measuring tape when the channel prof le 

 is measured, so should not be driven to ground level. Cross-section' 

 when established, should be roughly perpendicular to the banks! SeCti ° tU " 



6. Number the cross-sections consecutively from downstream to upstream (the 

 downstream-most cross-section is #1). upstream (the 



Measure the distances between cross-sections. This is an optional 

 measurement that might be useful in locating cross-sections during're^n 



Remember, the WETP model is invalidated if channel changes occur in the 

 study area during the data collecting process. For this reason the 

 collection of all field data should be completed during S per 

 beginning when runoff is receding and ending with the onset of runorf the 



5-2 



