Sedimentation Reports 1989 DNR Trego Flowage Study on Sedimentation Ripley Engineering Sediment Collection 3 1993 Ripley Engineering Update 11 1993 Preliminary Notes on the Trego Lake Sedimentation Study Engineering report NSP Response on Dredging 9 1994 1998 Army Corps of Engineers Letter 1994 Letter 2002 DNR Letter RE: Drawdown 2002 DNR Response to Drawdown Request 2002 Xcel Energy Letter 2003 Dept. of Interior Letter 2003 Sediment Committee Report 2004 Letter and Map 2005 Annual Meeting Report