TUALATIN RIVER FLOW MANAGEMENT TECHNICAL COMMITTEE 2016 Annual Report prepared by Bernie Bonn for TUALATIN RIVER FLOW MANAGEMENT TECHNICAL COMMITTEE 2016 Annual Report Prepared by: Bernie Bonn For: Clean Water Services In cooperation with: Oregon Water Resources Department, District 18 Watermaster FLOW MANAGEMENT TECHNICAL COMMITTEE MEMBERS Kristel Griffith, Chair City of Hillsboro Water Department John Goans Tualatin Valley Irrigation District Jake Constans Oregon Water Resources Department Jamie Hughes Clean Water Services Raj Kapur Clean Water Services Laura Porter Clean Water Services Scott Porter Washington County — Emergency Management System Mark Rosenkranz Lake Oswego Corporation Brian Dixon City of Forest Grove Todd Winter Washington County Parks — Hagg Lake ACRONYMS USED IN THIS REPORT FULL NAME ACRONYM FULL NAME ACRONYM Facilities Units of Measurement Spring Hill Pumping Plant SHPP Acre-Feet ac-ft Wastewater Treatment Facility WWTF Cubic Feet per Second cfs Organization Micrograms per liter g/L Barney Reservoir Joint Ownership BRJOC Milligrams per Liter mg/L Commission Million Gallons per Day MGD Clean Water Services CWS Pounds lbs Joint Water Commission JWC River Mile RM Lake Oswego Corporation LOC Water Year WY Oregon Department of Environmental Quality ODEQ Water Quality Parameters Oregon Department of Fish and Wildlife ODFW Biochemical Oxygen Demand BOD Oregon Department of Forestry ODF Dissolved Oxygen DO Oregon Water Resources Department OWRD Sediment Oxygen Demand SOD National Marine Fisheries Service NMFS Other Tualatin Valley Irrigation District TVID Biological Opinion BiOp Tualatin Valley Water District TVWD Total Maximum Daily Load TMDL Bureau of Reclamation BOR Wasteload Allocation WLA U.S. Fish and Wildlife Service USFWS U.S. Geological Survey USGS Disclaimer This report and the data presented herein are provided without any warranty, explicit or implied. The data pre- sented in this report were supplied by the members of the committee. Although every effort was made to faith- fully reproduce the data as provided, the data are not warranted to be accurate, appropriate for interpretation, merchantable, or suitable for any particular purpose. 2 2016 Tualatin River Flow Managment Report TABLE OF CONTENTS 2016 Summary . 4 Background Basin Description and Tualatin River Basin Map . 5 Tualatin River Water Management . 8 Member Reports for 2016 Reservoir Status . 10 Clean Water Services . 12 Joint Water Commission/Joint Barney Commission . 21 Lake Oswego Corporation. 27 Oregon Water Resources Department . 31 Scoggins Dam/Henry Hagg Lake . 34 Tualatin Valley Irrigation District . 37 Wapato Lake . 39 Water Quality. 40 Appendices A. Stream Gage Records—Data Tables and Hydrographs of Daily Data B. Selected Releases and Withdrawals—Data Tables and Hydrographs C. Scoggins Reservoir (Henry Hagg Lake) Operations—Monthly Data Reports D. Barney Reservoir Operations—Monthly Data Reports E. Municipal Water Use Allocations—Monthly Data F. Temperature Records—Data Tables and Graphs of Daily Data G. Reserved for special topics — none in 2016 H. Precipitation Records— I. River Mile Indices— 2016 Tualatin River Flow Management Report 3 2016 SUMMARY This is the twenty-eighth year that the Tualatin River Flow Management Technical Committee has pre- pared an annual report documenting the flow management of the Tualatin River. Members of the commit- tee include Clean Water Services (CWS), Tualatin Valley Irrigation District (TVID), Joint Water Commission (JWC), Lake Oswego Corporation (LOC) and Oregon Water Resources Department (OWRD). Highlights • Both Scoggins and Barney Reservoirs filled. • Weather highlights: –June was particularly hot with several days of 90 ºF temperatures. –October was particularly wet. Only 2 days in October did not have measurable rainfall. Total rain for the month set all-time records at several sites. • The primary pump used to drain Wapato Lake failed, but a concerted effort by several agencies brought in auxiliary pumps and the lake was drained on May 1, only one day past the deadline. • Regulation of river water ended earlier than usual (October 12th) due to high flows caused by the rainy weather. Tualatin River at Farmington (RM 33.3 #14206500) 1989–2016 40000 2016 1996 10000 2001 Statistical Distribution 1989–2016 90th percentile 75th percentile 1000 median 25th percentile Daily Mean Discharge (cfs) 10th percentile 100 60 1/1 2/1 3/1 4/1 5/1 6/1 7/1 8/1 9/1 10/1 11/1 12/1 Date 12/31 4 2016 Tualatin River Flow Managment Report BACKGROUND Basin Description The Tualatin River Basin comprises an area of 712 square miles situated in the northwest corner of Oregon and is a subbasin of the Willamette River. The headwaters are in the Coast Range and flow in a generally easterly direction to the confluence with the Willamette River. The basin lies almost entirely in Washington County. (See map below) The Tualatin River is about 80 miles long and changes dramatically from its headwaters to its mouth. The mountain or headwater reach (upstream of RM 55) is narrow (about 15 ft) and steep with an average slope of about 74 ft/mi. The meander reach (RM 55–33) is wider with an average slope of about 1.3 ft/mi. The reser- voir reach (RM 33–3.4) is very wide (up to 150 ft) and has an estimated slope of only 0.08 ft/mi. It includes several deep pools. Travel times through this reach are very long. The slow movement of the water causes this reach to act much like a lake. In the riffle reach (RM 3.4–0), the Tualatin River flows through a short reservoir section and then drops into a narrow gorge near the City of West Linn before it enters the Willamette River just upstream of Willamette Falls. The average slope in this reach is 10 ft/mi . Tualatin River Basin 123°22'30'' 123°15' 123°00' 122°45' 122°37'30'' 26 WASHINGTON COLUMBIA 45°45' E a s W t e s t T U E A WASHINGTON G L C k A F e O N o r e T k r MULTNOMAH L F C I U A Gales o N M r k B R IA R IV M W E R O I L C Banks North U L re N A ek Plains TILLAMOOK T M E A T OREGON y I T a N E K S D c 5 a M T ir y ek S re k C Cr e n A ee e o k r s S on c C r k O o Cornelius Hillsboro B e g re g Forest C C RM k in c ill s Grove o Be 50 R ave r M Henry rt a 26 on ed 45°30' Hagg Dilley C R ternut Cr Creek Lake UALATIN IVER ut T B Beaverton RM R I RM C RM Creek 40 V 60 E 70 Cherry H F ense a R Grove E rist n C Farmington n Ch ree n Gaston H k o Barney C A k RM Tigard r Reservoir ee e Ba L r 30 ek Oswego si E rris C Lake n Bu RM bou Wapato M Scholls nda Lake Creek 20 RM ry o 10 g M M l cF e ee a O w n s Cr a U B Tualatin O C N a r YAMHILL k rg C n e T e Nyb 205 o r A t k C e I a re N r S e C H n Sherwood West e Linn Portland k ic Study C h RM area 0 OREGON CLACKAMAS N T 0 510 MILESI T A E T R N 0 5 10 KILOMETERS R U A O P 5 M 45°15' Base modified from U.S. Geological Survey 1:100,000 topographic quadrangles, 1978–84 RM River mile Designated urban growth area from Metro, 2009 10 2016 Tualatin River Flow Management Report 5 Water sources to the Tualatin River Precipitation: Seasonal rainfall accounts for most of the natural flow in the Tualatin Basin; streamflow from snowmelt is minimal. The amount of rainfall ranges from 110 inches on the eastern slopes of the Coast Range to 37 inches in the southeastern area of the drainage basin. Peak months for rainfall are November through February while the driest months are normally June through October. The peak streamflow month is usually February and the lowest streamflow month is August. Barney Reservoir: Barney Reservoir is located behind Eldon Mills Dam on the Middle Fork of the North Fork of the Trask River (outside of the Tualatin Basin). A trans-basin aqueduct carries water over a low Coast Range divide to a pipeline that discharges into the Tualatin River at RM 78. Barney Reservoir has a capacity of 20,000 acre-feet and stores water for the Joint Water Commission (Cities of Hillsboro, Forest Grove and Beaverton, and the Tualatin Valley Water District) and Clean Water Services. The Barney Res- ervoir Joint Ownership Commission owns, operates and manages Barney Reservoir. Reservoir content is monitored through calibrated reservoir elevations; water releases are monitored using a stream gage located in the outlet flume. Water is released during the summer low-flow season to supplement shortages in natural flow. The water is used for municipal supply and for instream water quality. Storage in Barney Reservoir is also allocated to the Oregon Department of Fish and Wildlife. Those flows, to the Trask River, are measured using an instream weir. Scoggins Reservoir: In the early 1970s the Bureau of Reclamation built an earthen dam on Scoggins Creek (RM 5.1). Releases from Scoggins Reservoir (Henry Hagg Lake) flow down Scoggins Creek and enter the Tualatin River at RM 60.0. Scoggins Reservoir has an active storage capacity of 53,323 acre- feet. It is a multipurpose facility with contracted water for irrigation, municipal and industrial, and water quality uses.