01 



To: D.J. Bakken, Forester, Helena Unit 



cc: Jeff Collins, Soil Scientist, Forest Management Bureau 



Gary Frank, Hydrologist, Forest Management Bureau 

 Bill Schuitz, Supervisor, State Land Management Section 

 Garry Williams, Manager, Forest and Lands Program 



FROM: George Mathieus, Hydrologist, Forest Management Bureau 



SUBJECT: Gladstone Timber Sale, Hydrologist Report 



DATE: July 9, 1998 



Hydrology Existing Conditions/Effects Analysis 



Gladstone Timber Sale 



T15N-R5W Sections 23. 26, 28, 34 



Central Land Office, Helena Unit 



INTRODUCTION 



The following document contains background information for the watershed and hydrology portions of the 

 proposed Gladstone Timber Sale E.A. This analysis will encompass three action alternatives and a no- 

 action alternative. Writeup and assessments are based on a coarse filter screening approach, a water yield 

 analysis, and an on-site field review of all contributing drainages within the proposed sale area. 



POTENTIAL ISSUES 



Water Quality: 



Land management activities such as timber harvest and road construction can impact water quality 

 primarily by accelerating sediment delivery above natural levels to local stream systems. These impacts 

 are caused by erosion from road surfaces, skid trails and log landings and by the removal of vegetation 

 along stream channels. 



Cumulative Watershed Effects: 



Cumulative watershed impacts can be characterized as impacts on water quality and quantity that resuU 

 from the interaction of disturbances, both human-caused and natural. Timber harvest can affect the timing 

 of runoff, increase peak flows, and increase the total annual water yield of a particular drainage. The 

 amount of water yield increase is proportional to the percentage of the forest canopy removed from the 

 watershed. In some cases, increased water yield brings about increased peak flows which may result in 

 physical damage to stream channels, thus causing instability, loss of fish habitat, and downstream water 

 quality impacts. The degree to which these effects occur depends on the interaction of many variables 

 including soils, bedrock geology, the size and timing of storm events, harvest prescription and project 

 design. 



AFFECTED ENVIRONMENT 



Setting: 



The proposed timber sale area is located across four different parcels of State land that lie within both the 

 French and Gladstone Creek watersheds. Both drainages are tributaries to Wolf Creek near Wolf Creek, 

 Montana, approximately 34 miles Northwest of Helena, Montana. State ownership is entirely surrounded by 



