domestic water supply, lawn and 

 garden sprinkling, industrial and 

 commercial uses, coldwater 

 fisheries, and recreational use in 

 the stream, wetlands, lake, and 

 surrounding area. 



Water-Quality-Limited Waterbodies 



The Dog Creek watershed is not listed 

 in either the 1996, 2000, or 2002 LIST 

 OF WATERBODIES IN NEED OF TOTAL 

 MAXIMUM DAILY LOAD (TMDL) DEVELOPMENT 

 publication produced by DEQ (2003a, 

 2003b, 2003d) . 



Montana SMZ Law 



By the definition in ARM 36.11.312 

 (3) , the majority of the Dog Creek 

 watershed is a class 1 stream. Dog 

 Creek and many of its tributaries flow 

 for more than 6 months each year. 

 Many of these stream reaches also 

 support fish. Some of the smaller 

 first -order tributaries may be 

 classified as class 2 or 3 based on 

 site-specific conditions. 



SEDIMENT DELIVERY 



According to field reconnaissance in 

 the summers of 2000 and 2002, stream 

 channels in the Dog Creek watershed 

 are primarily in good condition. 

 Three reaches were rated in fair 

 condition, and one in fair/poor 

 condition. The reason for the 

 reaches rating fair and fair/poor 

 was deposition. Gravel bars have 

 formed on point bars in these 

 reaches. No areas of in-channel 

 erosion were identified during field 

 reconnaissance. Large woody debris 

 was found in adequate supply. 

 Little evidence of past streamside 

 harvesting was found; where past 

 logging in the riparian area had 

 taken place, no deficiency was 

 apparent of existing or potential 

 downed woody material in the 

 streams . 



The existing road system in and 

 leading to the proposed project area 

 was reviewed for potential sources 

 of sediment. Stream crossings in 

 the project area and on the haul 

 route are generally in good 



condition and not contributing 

 sediment to streams . Many have been 

 replaced and brought up to 

 applicable BMP standards through 

 other projects. Some crossings need 

 additional BMP work and some need to 

 be replaced. Surface drainage BMPs 

 on the existing road system need to 

 be upgraded to meet applicable 

 standards. In spite of the minor 

 surface drainage and erosion-control 

 measures needed on the existing road 

 system, no sources of direct 

 delivery of fine sediment were 

 identified through field 

 reconnaissance . 



WATER YIELD 



The allowable water-yield increase 

 for the Dog Creek watershed has been 

 set at 12 percent, based on channel - 

 stability evaluations, watershed 

 sensitivity, and acceptable risk. 

 This water-yield increase would be 

 reached when the ECA level in Dog 

 Creek reaches the allowable level of 

 2,838. Detailed information is 

 available for timber harvesting and 

 associated road construction 

 activities that have taken place in 

 the Dog Creek watershed since the 

 1960s. These activities, combined 

 with the vegetative recovery that 

 has occurred, have led to an 

 estimated 4.9 percent water-yield 

 increase over an unharvested 

 condition in the Dog Creek 

 watershed. TABLE D-1-CURRENT WATER 

 YIELD AND ECA INCREASES IN DOG 

 WATERSHED summarizes the existing 

 conditions for water yield in the 

 Dog Creek watershed. 



TABLE D-1 - CURRENT WATER YIELD AND 

 ECA INCREASES IN DOG WATERSHED 



Appendix D-Hydrology Analysis 



Page D-3 



