In general, variation in loading was more affected by discharge than concentration, and 

 linkages between land-uses such as grazing and loads cannot be made with the exception 

 that irrigation withdrawals exert a strong influence over discharge and loads earned by 

 Lost Creek. In addition, groundwater return in the area above Station 8 likely results in 

 both increased flow and nitrogen rich water from multiple sources. In this case, 

 groundwater (which may include loads from land application of wastewater) and 

 Dutchman Creek, may represent the largest TN loads to the system based on flow 

 contribution and concentration of nitrate. 



Riparian Health Assessment 



Results of riparian inventories are summarized in Table 5 through 7 indicating the 

 health scores for vegetation, soils/hydrology and total health scores. Specific concerns 

 were listed under Problem Summary heading if category received a score of 33% or less 

 than its potential score. For example, if the infestation of invasive species resulted in an 

 actual score of 1 point out of a potential of 3 points it was included in the table as a 

 factor responsible for lowering the overall score for the polygon. 



Overall, 70 % of the polygons surveyed were scored as "not functionar, and the 

 remaining 30 % were scored as "functional / at risk". The greatest proportion of non- 

 functional polygons was found on the middle to lower reaches (see Map 2). In general, 

 the majority of polygons exhibited severe noxious weed problems (mainly thistle), loss of 

 woody vegetation and/or over-utilization of woody vegetation. In addition, bank 

 instability caused by the loss of deep binding rootmass and trampling of banks by cattle 

 were common problems. 



Lateral cutting and channel incisement were commonly observed, with several 

 reaches possessing moderate headcuts and channel braiding in heavily impacted areas. 

 Cannel bottom composition of fine sediment was also calculated by summing silt and 

 sand coverage from lotic inventories. Fine sediment coverages ranged from 13% to 80% 

 of total bottom cover, with the highest coverages observed in the middle to lower reaches 

 below the Dutchman reservoir. 



As mentioned above, riparian health assessments were performed to provide a current 

 inventory and health evaluation of vegetation and soil/hydrology processes. Ideally, the 

 RWRP Lotic Inventories will be performed on a periodic basis to gauge the success of 

 the proposed restoration. As such, the health scores (70% not functioning, 30% at risk) 

 derived in this study re-emphasize the need for habitat improvement in the 

 basin and should help managers focus on areas of concern. Although the results of the 

 health assessments are consistent with problem areas identified by the MDFWP, detailed 

 information in the Lotic Inventory form, such as noxious weed infestation, shrub 

 regeneration, and vegetation cover and type, should prove invaluable to managers 

 developing the grazing management and riparian restoration plans on Lost Creek. 



