12.0305.00 Cedar Creek 1.1 14-16-5W From mouth to headwaters. There is no estimate for reopening and no good detours. If you live in Rochester, Grand Mound, Oakville, Fords Prairie or Centralia you're less than 10 miles from Chehalis River. A large flow on the Chehalis at Grand Mound can happen with or without a significant flow contribution from the Skookumchuck River. He noted that lowered groundwater levels have been problematic for Oregon Spotted Frog in some areas upstream. Chehalis River Basin Early Warning System. There is no estimate for reopening and no good detours. Chehalis River water quality would be significantly affected from the removal The proposed project reduces the flood levels at the Chehalis-Centralia airport by 50% for a catastrophic flood The reduction in damage would be accomplished without causing increased flood damage in other areas. THE CHEHALIS RIVER BASIN . Other local waterways were not expected to flood as of Sunday afternoon. It includes northwestern Lewis County, southeastern The Chehalis River at Grand Mound was predicted to crest just below minor flood stage on Tuesday. River levels around the region are dropping across the board, with the exception of the Chehalis River at Grand Mound, which is projected to continue rising until 6 Peak flows on the Newaukum River and South Fork Chehalis are similarly correlated to the Major Road closures and residential flooding. ORIGINAL POST: In case you hadn't heard, a 20-mile stretch of I-5 in Lewis County between Grand Mound and US 12 south of Chehalis is now CLOSED in both directions due to rising flood water from the Chehalis River. Nisqually River: near National / Mineral Cr / at La Grande / Centralia Canal / at McKenna. Moderate flooding (individual residences are threatened) occurs at about 142.53 feet, and major flooding (widespread threat to communities and major thoroughfares) at about 144.03 feet. National Weather Service Continuous water levels in wells, stream stage at U.S. Geological Survey streamflow gaging station 120227500, Chehalis River at Grand Mound, and total monthly 0 2 4 8 10 12 2 4 6 8 10 GROUNDWATER ELEVATION AND STREAM Well Stage Stream Stage APRIL 2010 Water levels in well 17N/07W-08K02 and stream stage at 2. Mr. The highway will be closed from Exit 88 near Grand Mound to exit 68, about 11 miles south of Chehalis. Were seeing many rivers and streams in Ssouthwest Washington run at record low levels. Prepared for Chehalis River Basin Flood Authority Lewis County Board of County Commissioners 315 NW North Street, Rm. reach of the Chehalis River in Thurston County near Grand Mound and Rochester. This is well below the Flood Stage at this gage. The Chehalis River at Porter is expected to crest at 52 feet Saturday afternoon, nearing a record high level. Location: In NE 1/4 NE 1/4 sec.22, T.15 N., R.3 W., Thurston County, on left bank at downstream side of highway bridge at Meadows, 1.5 mi southwest of Grand Mound, 7.0 mi downstream from Skookumchuck River, and at mile 59.9. in this area due to flooding since 1996 and Water data back to 1928 are available online. There is no estimate for reopening and no good detours. A Water Quality Study . The community is bounded by the Chehalis River to the southwest and by the freeway to the east. Please delay travel if possible until flood water recedes. Monitoring location 12027500 is associated with a STREAM in THURSTON COUNTY, WASHINGTON. Joel Green, Ph.D. Don Loft, B.A. Pertinent physiographic data for the basin are given in table 1. Updated hourly.

City of Chehalis Washington 350 N Market Boulevard Chehalis, WA 98532 (360) 345-1042 CHEHALIS RIVER NEAR GRAND MOI_INOAA (12027500) +Gageheight (1806120006b) n Major Flood Stage: 14400 f: 14280 JModerate Road Stage: 14250 ft Stage: 141 00 ft 140.00 -C]High Water Alert Triggered: 140 00 ft Nav 2020 2020 132.so 12/ so Oct 01.2020 act 2020 Dec 01, 2020 00:0000 Dec 16.2020 Jan 2021 1. measured at the Chehalis River between the Newaukum and Skookumchuck Rivers. There is currently no estimated time for reopening. Major Road closures and residential flooding. Some Road closures, but no major flooding.

The Chehalis River near Grand Mound is running at 113 cubic feet per second a flow level in the 1st percentile, meaning flows are so low they are exceeded 99 percent of the time for this time of year historically. Comments or questions can be directed to Scott Boettcher, Chehalis River Basin Flood Authority, 360/480-6600, scottb@sbgh- partners.com. Graphs for All Rivers. The Chehalis River gauge near Grand Mound is forecast to crest at over 145 feet early Saturday morning, which is at major flood stage and would be the second-highest crest ever recorded. Mid-century: 2%. Lewis County hard hit by flooding. Deschutes River: near Rainier. River Mile and Section, Township and Range Affected Stream Reach Including Tributaries 12.0275.00 Chehalis River at Grand Mound 59.9 22-15-3W From confluence with Newaukum River to confluence with Prairie Creek. Figure 1). HTML PDF: 173-522-010: From confluence with Prairie Creek near Grand Mound to confluence with Porter Creek including Prairie Creek. The Chehalis River Basin upstream of Grand Mound covers an area of 772 square miles in Western Washington. Level 5+/- . and industrial needs of the 895-square mile upper Chehalis River Basin upstream of Grand Mound, Washington, while providing streamflow for fish and other aquatic species in the Chehalis River and its tributaries. A USGS gaging station (12027500) on the Chehalis River at Grand Mound has been operational four miles downstream of the Galvin Road Overflow bridge from 1929 - 2002. FERNDALE, Wash. A Whatcom News reader provided a video recorded via a drone today, November 16th, that shows some of the extent of the Nooksack River flooding while the river was at a level of about 23.4 feet. Mr. Mobbs said that cold water in the Black River could be beneficial. Olympic Peninsula: Quinault / Queets / Hoh / Elwha / Dungeness. By the time the Chehalis River reaches Grand Mound, the flow is five or six times higher than it was in Doty. 12.0325.00 From influence of mean annual high tide at low base flow levels to headwaters. The general pattern of tributary ground- and surface-water interaction was levels. Generally no road closures or residential flooding. A significant storm in the Basin in February 2017 brought the river flow up to 30,800 cfs at the Grand Mound gage. Although gauge readings and historical data are excellent forecasting tools, please remember that rivers continually change. Gage Information: Water-stage recorder. Although gauge readings and historical data are excellent forecasting tools, please remember that rivers continually change. . Groundwater and surface water collectively supply the domestic, agricultural, and industrial needs of the 895-square mile upper Chehalis River Basin upstream of Grand Mound, Washington, while providing streamflow for fish and other aquatic species in the Chehalis River and its tributaries. The Galvin site is more The Chehalis Tribe is doing work at the mouth of the Black River, an area that spring Chinook hold over the summer. On the Satsop and Wynoochee, flooding is generally closer to a 5 to 10-year event when the mainstem Chehalis is experiencing its highest floods. Chehalis River Above Grand Mound affecting Grays Harbor and Thurston Counties. Flood waters receded much faster than expected. The update is being led by Erika Katt and Ross McDowell from Lewis County Emergency Management, guided by a group of stakeholders representing Lewis County, the cities of Centralia and Chehalis, the Port of Chehalis, Lewis County Water District Period of Record: October 1928 to current year. Since 2008 nitrate levels have dropped throughout the aquifer. The fishing regulatory body for Washington is Washington Department of Fish and Wildlife. There is also a slight chance of record flooding in the Grand Mound/Porter areas from the Chehalis River on late Friday into Saturday. Grand Mound gage. Do not attempt to cross water covered bridges, dips, or low water crossings. In Porter, with the additional waters of the Black River added, flows vary from 419 in August up to 9,500 cfs in January. July 2013. in the Chehalis River basin, water years 1962-65 _____ 44 6. 4. USGS 12027500 CHEHALIS RIVER NEAR GRAND MOUND, WA. In Porter, with the additional waters of the Black River added, flows vary from 419 in August up to 9,500 cfs in January. SEATTLE - After horrible flooding in Lewis County, most river levels are expected to recede this weekend. 3. Map of the Chehalis River Basin above Grand Mound_____ 112 43. U.S. Geological Survey streamflow-gaging station 12027500, Chehalis River at Grand Mound, and total monthly precipitation at Centralia, Graph showing water levels in well 17N/07W-08K02 and stream stage at . Some Road closures, but no major flooding. These include the lower 6 miles of the South Fork Chehalis River below Lost Valley Road, 11 miles of the Current conditions of DISCHARGE and GAGE HEIGHT are available. By the time the Chehalis River reaches Grand Mound, the flow is five or six times higher than it was in Doty. Latitude: 46^46'34"; Longitude: 123^02'04" Water-stage recorder. Water discharges and measured maximum and minimum in Chehalis River near Grand Mound (275) __.__ 895 Black River near Oakville (292) _____ 136 from sea level to about 5,000 feet. helped to protect the water resources. The Chehalis River exhibited a pattern of alternating gains and losses as it entered the area of wide, gentle relief known as the Grand Mound Prairie. According to a news release, the Chehalis River near Grand Mound has been rising due to heavy rainfall and will continue to rise to reach minor flood stage this evening. Please delay travel if possible until flood water recedes. Black River, along Beaver Creek near the railroad and Interstate 5, along the Chehalis River close to Grand Mound, and in places along Scatter Creek due to rural development. All river levels can be closely monitored here. The Chehalis River above Grand Mound will cause major flooding, inundating roads and farmlands in the Independence Valley. References to non-Department of the Interior (DOI) products do not constitute an endorsement by the DOI. A large flow on the Skookumchuck is not a very good indicator of large flows downstream at Grand Mound. Some Road closures and minor residential flooding. USGS Soil-Water Balance (SWB) Model Accounts for spatial distribution of soil properties and land cover Daily calculation of evapotranspiration, groundwater recharge, and surface runoff 500-foot grid cell Hydrograph Separation USGS Gage at the Chehalis River Near Grand Mound Daily calculation of surface- runoff and baseflow Groundwater and Surface-Water Use It originates in several forks in southwestern Washington, flows east, then north, then west, in a large curve, before emptying into Grays Harbor, an estuary of the Pacific Ocean.