tva south holston lake levels

You can cancel at any time. More information about fisheries activities in the Tennessee portion of South Holston Reservoir can be obtained athttp://www.tnfish.org/Anglers/SHolstonAngler.htm. Casting crankbaits at night is one of the most popular methods. Check lake levels all over the United States. Location: A small pullover/ parking area is available on Rt. South Holston: The South Holston watershed area will need approximately 3.0 inches of rain between now and June 1 for the lake to reach an elevation of 1,729 feet. But many people are interested in tailwater recreationwhitewater rafting, canoeing, kayaking and fishing in the area downstream from TVA dams. David Crigger/Bristol Herald Courier Area. During the summer, troll spoons at 30 to 50 feet deep for rainbows and browns and 90 feet deep for Lake Trout. South Holston is operated for several purposes, including flood damage reduction, power production, aquatic ecology, and augmentation of the flow of water during drier periods. In 1991, TVA built a weir below South Holston Dam to add oxygen to the river when the hydropower plant isnt generating electricity. This massive earth and rock structure holds back the waters of South Holston Lake which extends some 24 miles up the river from the dam. 7 trout creel limit, only one trout may be greater than 22 inches. As mentioned above, we will begin sharing this information with neighbors and the public in the coming days. Anglers fishing for crappie congregate in the headwaters of the lake during late winter and early spring. Anglers enjoyed some great walleye fishing in the rivers during March of 2004. 2015 - Bristol . With prime boating season near, lake enthusiasts need to be careful when operating a boat at South Holston Lake because the lake is lower than normal, Tennessee Valley Authority officials the parking lot below the dam leads to Osceola Island and its one-mile-loop Burton ends Honaker's state title reign; Taylor Clay scores 29 in Eastside victory, In Tennessee, a Medicaid mix-up might land you on a most wanted list, LOCALS IN COLLEGE NOTES: Lomax to run next for UVa-Wise. Smallmouth move to deeper water in the summer and this is a good time for night fishing with various worm rigs and pig-n-jig. The annual cost of the South Holston License is currently $21 dollars. Generally, walleyes exceed 10 inches in their first year, measure 17 inches in their second year, and reach 20 inches by their third year. Hotel Zur Post Ismaning - Traveller rating: 4.0/5. The dam was completed in 1950 and impounds 24 miles of the South Fork Holston River. The Virginia State Police continue to investigate a fatal single vehicle crash that occurred Tuesday in Wise County. Should you have any questions or concerns, feel free to contact me directly. Everyone agreed being able to play league ball this spring would give him a sense of normalcy. (renews at {{format_dollars}}{{start_price}}{{format_cents}}/month + tax). . A ten-inch minimum size limit has been established for crappie in South Holston Reservoir. Since both lake and river spawning fish have been stocked, some Walleye make a spawning run to the headwaters of the reservoir. Leverage your professional network, and get hired. Building resumed in 1947 and was completed in 1950. E-mail the office, Go to Tennessee Wildlife Resources Agency. A wide network of trails with prolific . As of now, the impacts are focused in northeast Tennessee and southwest Virginia and include Norris, Cherokee, South Holston and Boone Lakes. Tail waters usually call for long, light, fly rods. Also, troll spoons in the main channel. Many anglers begin the season fishing for migrating crappie in the old river channel near the Whitaker Hollow boat landing. 2020 South Holston Reservoir Popular Report, http://www.tnfish.org/Anglers/SHolstonAngler.htm, 2023 Virginia Department of Wildlife Resources. There are some very nice flathead catfish available. The Virginia State Police continue to investigate a fatal single vehicle crash that occurred Tuesday in Wise County. Bank fishing with corn, salmon eggs, or other live bait is productive when the water is cool. The water comes from the bottom of South Holston lake, and is nice and cold. A footbridge from Hundreds of miles of lake shoreline and water await the fisherman, boating enthusiast, skier, and nature lover. LakeLevels.info is a national information and alert service for lake water levels in the United States. Construction of the We typically will see about 3 to 4 feet of drop per month over a three- or four-month period. South Holston Dam, at a whopping 285 feet high and 1,600 feet in length, is the third-largest earthen dam in the world. It has one generating unit with a net dependable capacity of 44 megawatts. South Holston Reservoir Fishing License Available South Holston Lake is a 7,580-acre impoundment operated by the Tennessee Valley Authority (TVA). Biologists say the river boasts fish populations of 8,500+ fish per mile. wildlife trail. As soon as the rain stops, people can expect heavy water flow for several more weeks., nshepherd@bristolnews.com | 276-645-2567 | @nickshepherd240 | Facebook.com/nickshepherd2406. The water will be released to recover the flood storage currently being used. About fifty percent of the bass collected exceed 15 inches in length. rods are the most popular. Quick Links Boone Lake News Be very careful when wading. The reservoir is loaded with sought after sportfish, including smallmouth bass, largemouth bass, white bass, crappie, and walleye, in addition to foraging fish, like gizzard shad and alewives. Coordinates: 36.5697, -82.0153. Nine foot5wt. The South Fork Holston Construction of the dam began in 1942 but was halted in favor of other wartime construction efforts. Bristol Convention & Visitors Bureau. "Award winning guide service located in East Tennessee". Northern watersnake and snapping turtle also frequent the area. There is no size limit on trout and the daily creel limit is seven trout in any combination, except only two can be Lake Trout. In winter and during migration the area supports a variety of shorebirds and waterfowl, while bald eagle are possible throughout the year. Our online news carries on the tradition of Southern Fishing dating back to the late 1970's with the Southern Fishing Television Show, then the print publication Southern Fishing. TVA says water levels at South Holston, Watauga, Cherokee, Norris, Tims Ford, and Nottely reservoirs will exceed summer pool levels as tributary dams store water to prevent flooding downstream. Although South Holston is not highly fertile, Smallmouth Bass from this reservoir grow large and are in excellent condition. In a year with normal rainfall, the water level in South Holston Reservoir varies about 25 feet from summer to winter to provide seasonal flood storage. TVA debt securities are secured by revenues from its power system and are issued only for power program purposes, including refinancing of existing debt. Construction South Holston, Boone projects to take several years. |Privacy Policy|News. The cold, deep waters of the South Holston Lake keep water at a constant enough temperature to ensure good fishing conditions year round. South Holston Lake is a big draw for area anglers. Boone and Fort Patrick Henry Fisheries Management PlanPrepared by: Tennessee Wildlife Resources Agency iii 2. (renews at {{format_dollars}}{{start_price}}{{format_cents}}/month + tax). During spring, use spinner baits, buzz baits, lizards, 4-6 inch worms and Flukes, small Shad Raps, Bandit crankbaits and stick baits. You can not wade fish when the river is at generationflow. Boone Lake reached its optimal summer pool level during the July 4 weekend and has remained about that level. The plan at South Holston is to follow its normal drawdown, Everett said. The earth-and-rockfill dam is 285 feet high and reaches 1,600 feet across the Virginia residents fishing in South Holston Lake in TN must have a Virginia resident license and South Holston Reservoir Permit (or Tennessee non-resident fishing license); under the age of 13-no license or permit required. The average water temperatures do not vary 10 degrees from winter to summer. operated for several purposes, including flood damage reduction, power production, It is currently releasing approximately 420 feet of water every hour. Download the TVA Lake Info app, an easy-to-use resource for . A mosaic of mudflats, flooded forest and open woodland offers a real boon for wildlife watchers. The white bass population has declined sharply since 1998. Oxygen-rich water helps create a sustained habitat for aquatic insects, vegetation, and fish. The South Holston License is valid in all impounded portions of the reservoir below full pool elevation of 1,730 feet, including the confluence of the Middle Fork and South Fork Holston rivers and the South Fork Holston River upstream to the Route 710 Bridge at Alvarado, VA. Stocking efforts will continue in the future when broodstock are available. In 1991, TVA built a labyrinth weir below the dam to introduce oxygen to the river when the hydropower plant isn't generating electricity. The watershed areas of Norris, Cherokee, Boone and South Holston Lakes will require above normal rain and runoff for those lakes to reach June 1 recreation levels. The cost of repairs going on at the two dams isn't cheap, $450 million at Boone and $30 million at South Holston, but TVA officials say the . Nearby South Holston Lake, whose waters are used for power generation and to provide water supply and water quality downstream, operates on a different guide curve than Boone. Largemouth bass: Fish in the upper end of the reservoir. The reservoir has relatively low productivity and water clarity is normally greater than most other Tennessee reservoirs. Get up-to-the-minute news sent straight to your device. The spring run of walleyes into the South Fork and Middle Fork Holston Rivers near the community of Alvarado is increasing in popularity. After walleyes return to the lake in late spring, anglers use a variety of lures and techniques to catch them. Everett noted this will be the first time in seven years that Boone has participated in the annual process, now that repairs at the dam were completed earlier this year. A special South Holston Lake permit is required to fish the waters. Size restrictions and creel limits shall be as follows: *All trotlines, limb-lines and jugs must be tagged with anglers name, address or license. South Holston offers good fishing for a variety of species. These hotels near Flycaravelle in Ismaning generally allow pets: Hotel-Gasthof zur Muehle - Traveller rating: 4.0/5. When the cheerleading coach broke the news to Katrina Kohel that she was the only one left on the cheer squad, Kohel was determined to compete anyway. South Holston Dam is a hydroelectric facility. This water comes from the South Holston Reservoir, this 7,550 acre lake resides mostly in Tennessee although 1,660 acres of the lake reside in Virginia. to the river when the hydropower plant isnt generating electricity. The black crappie population has made a strong comeback in recent years. Net dependable capacity is the amount of power a dam can produce on an average day, minus the electricity used by the dam itself. Catch rates for electrofishing and gillnet samples in 2004 were the highest recorded in recent years. 664. South Holston Lake is located in northeastern Tennessee and extends 24 miles into Virginia. Holston Reservoir is on the South Fork Holston River in northeast Tennessee. The Boone watershed area has seen about 75% of normal rainfall over the last 60 days. Jacobs Creek area would be a good place to start any crappie fishing trip. Station Number Station name Date/Time Gage height, feet Dis-charge, ft3/s Long-term median flow 2/28 Colbert County, Alabama We will continue to do all we can to move water and increase lake levels but as we all know, Mother Nature controls this right now. Find South Holston Dam at 918 South View Dam Dr., Bristol, Tenn. 37602. In a few days, TVA will begin outreach to the public through media and social media to share updates but before that begins, we wanted you to hear directly from us. This massive earth and rock structure holds back the waters of South Holston Lake which extends some 24 miles up the river from the dam. Download the TVA Lake Info app, an easy-to-use resource for operating on and around reservoirs and dams in the TVA region. The width of the river can range anywhere from sixty yards to one hundred yards, and is easily crossable when the TVA isn't generating. The Cherokee watershed area has seen about 75% of normal rainfall over the last 60 days. May 11, 2022. Get the most up-to-date information on each reservoir TVA manages, including todays levels, predicted elevations, planned generation releases at the dams, reservoir operating guides, ecological health ratings, fish population survey results, recreation facilities, and more. Toll-Free:1-800-332-0900 Address for GPS: 918 Holston View Dam Road, Bristol, TN. A valid resident Tennessee trout fishing license or a valid resident Virginia trout fishing license is required to fish for trout and to possess trout on South Holston Reservoir. Heres where you can get all the data you need to plan your day on the water. Subscribe to our Daily Headlines newsletter. One of the wettest Februarys on record is expected to continue with another 2-3 inches expected in the next few days. Well target the normal 1,382 through Labor Day, and its not a sudden or immediate drop in lake levels, it is gradual, Everett said. Lake Levels and Generation Schedules for Tennessee Dams. efforts. Before heading out to visit a site on the Virginia Bird & Wildlife Trail, be sure to check if that site has any COVID-19 policies or closures in place. More than 100,000 walleyes were stocked into the reservoir three out of the last five years. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Create a website or blog at WordPress.com, Click to share on Facebook (Opens in new window), Click to share on Twitter (Opens in new window), Click to share on LinkedIn (Opens in new window). 664/ Lake Rd, just east of its intersection with Green Springs Church Rd. Anglers who create or find brush piles submerged deep in the lake often catch crappie during the winter months. In the spring, look for downed trees and brush. TVA will be aggressive with some water releases at other dams they manage, he said. Water levels will begin to diminish after Labor Day, lowering slowly during September and then more briskly later into the fall, Everett said. With a FREE member account you can receive water level alerts by email when the water level reaches your desired alert level. These fry were produced at the Buller Fish Cultural Station in Smyth County. Planning to get out on the water today? Catch rates for black crappie began increasing in 1999. Sulphurs and Blue Winged Olives hatch nearly year round. He added that it will move a lot of water through the system to create storage in reservoirs like South Holston. South Holston Lake is a 7,580-acre impoundment operated by the Tennessee Valley Authority (TVA). Burton girls; Twin Springs boys win 2nd straight region title, Bristol-made items named among best of Virginia, REGION 2D BOYS: Virginia High, Graham earn state tourney berths, REGION 1D GIRLS: J.I. For U.S. Army Corps of Engineers Operated Reservoirs. On Tuesday, James Everett, senior manager of the TVA river forecast center in Knoxville, discussed plans for reducing water levels across the valley during a call with Tri-Cities area news media. However, dissolved oxygen can sometimes fall below optimum levels during the summer, limiting the success of the fishery, especially Lake Trout. View Seasonal Observations Submitted to eBird, TVA Access Area Mouth of Wolf Creek South Holston Lake, Site Contact: Tennessee Valley Authority: 1-800-TVA-LAND (1-800-882-5263), tvainfo@tva.gov, 2023 Virginia Department of Wildlife Resources. *Elevations are in feet above sea level. As the water temperatures rise, crappie head for the shallows to spawn. For more information contact the Marion VDGIF office. Net dependable capacity is the amount of power a dam can produce on an average day, minus the electricity used by the dam itself. Melinda A WatsonPartnerships and Strategic Integration Program ManagerNatural Resources. Whatever rate we go to, we will pick a flow rate that stays near those thresholds.. Cant access lake information? The daily creel limit is five Walleye with an 18-inch minimum size limit. This popular fishery is subject to high harvest, with most legal-sized fish getting creeled when They can also be caught suspended in the winter months using jigs with minnow imitating lures. ABINGDON, Va. An Abingdon, Virginia man faces drug charges after authorities seized a substantial quantity of methamphetamine. Levels of Boone Lake and other TVA area lakes will begin going down after Labor Day after a summer at full pool following repairs at the dam. The walleye population is also doing very well. In a year with normal rainfall, the water level in South Holston Reservoir varies about 25 feet from summer to winter to provide seasonal flood storage. Anglers who prefer trolling will also find a good selection of open water structure ranging from mud flats to river channel drop-offs to submerged islands. Current levels are 1,724 feet. Black crappie over 15 inches in length have been collected. 2016 was the most recent year we've seen similarly low levels at South Holston in May. This is a flood-control measure that will protect the Tri-Cities area from any catastrophic damage, said James Everett, senior manager for the TVA River Forecast Center. A 9ft6X leader with a fluorocarbon tippet is the best starting point for subsurface flies. We currently offer Lake Level information and alerts for 355 lakes and serve 21,396 members with 50,323 alerts. South Holston Reservoir Fishing License Available. We cant hold on to that water indefinitely, Everett said. Standard river Walleye fishing tactics (grubs, flies, and minnows) should work. Today's top 8 Tierklinik Ismaning jobs in Ismaning, Bavaria, Germany. {{start_at_rate}} {{format_dollars}} {{start_price}} {{format_cents}} {{term}}, {{promotional_format_dollars}}{{promotional_price}}{{promotional_format_cents}} {{term}}, BY NICK SHEPHERD | BRISTOL HERALD COURIER, Nebraska cheerleader competes by herself at state competition, but crowd doesn't let her feel alone, LOCALS IN THE PROS: Mac McClung back at the G League grind, Richlands altercation under investigation, REGION 1D BOYS: Lowe, Tigers roll past Eastside for state berth; Twin Springs trounces Grundy, VHSL HOOPS: Ryan Horne having senior year to remember for Twin Springs, REGION 2D GIRLS HOOPS: Defending champ Wise Central squeaks past Richlands; Gate City rolls past Ridgeview, REGION 1D: Fourth time the charm for J.I. Their corresponding flies will work wonders. Once the rain stops, Everett said there will be a very high water flow coming out of the South Holston Dam. TVA to begin lowering lake levels after Labor Day. South Holston Dam, an earth-and-rockfill dam, has one generating unit that has a net dependable capacity of 44 megawatts. In 1991, TVA built a weir dam, an aerating labyrinth weir, approximately 1.5 miles below the main dam, straddling the . The daily creel limit for crappie is 15-fish with a minimum length limit of 10 inches. This abundance of public land makes South Holston a haven for campers and bank anglers. 2016 was the most recent year weve seen similarly low levels at South Holston in May. All of TVAs large tributary reservoirs, including South Holston, Watauga, Norris, Fontana, Cherokee and Douglas in Northeast Tennessee, begin releasing water for flood control, Everett said. Well stop at roughly that 1,362 mark as the normal guide curve shows.. Levels of Boone Lake and other TVA area lakes will begin going down after Labor Day after a summer at full pool following repairs at the dam. Fly Fishing is extremely popular in South Holston River, a nationally recognized trout fishery. In 1991 the TVA added a weir below the dam to support the fish populations by oxygenating the water when the dam isn't generating power. Turn left on Rt. A footbridge from the parking lot below the dam leads to Osceola Island and its one-mile-loop wildlife trail. Winter drawdowns are severe and water levels can fluctuate 40 feet below the summer pool. Description. Early in the morning or late in the evening are the best times to sight waterfowl, deer, and other wildlife. See accompanying text summary for forecast statements. During the Spring and Summer months, TVA usually follows a generation schedule designed to not interfere with fishing . Due to record rainfall that has soaked the region, the Tennessee Valley Authority will only release minimal amounts of water at South Holston Dam over the next few days, a TVA official said on Thursday. This pattern produces fish throughout the summer months and into early fall. South Holston Lake is located in Sullivan County in Tennessee. 7486 surface area (acres) 228 max. Get up-to-the-minute news sent straight to your device. Right now, were at elevation 1,725, and our December flood guide target is elevation 1,708 thats about a 17-foot drawdown well expect to see.. to Hwy. Boone: The Boone watershed area will need approximately 1.5 inches of rain between now and June 1 for the lake to reach an elevation of 1,382 feet. Normal water levels during the winter are 1,692 feet. Recent stocking efforts seemed to have improved crappie angling within the reservoir. Some anglers find fish in the reservoir, but most concentrate in the headwaters of the lake. One of the side effects is we are going to see lake levels climb, Everett said. When the reservoir levels start to drop, walleyes have to leave the cover and often congregate on offshore structure. 2016 was the most recent year weve seen low or lower levels at Norris in May. Building resumed in 1947 and was completed in 1950. Much of the reservoir is in Tennessee, but the Virginia portion of the reservoir offers anglers more than 1,600 surface acres of water. You can either park here, or go a little further and park in the next parking area on your left. 2016 was the most recent year weve seen low or lower levels at Cherokee in May. This method is very effective for catching bass that are suspended in the water column. When the reservoir stays full, walleyes tend to hang tight in shoreline cover. trout. Locals say South Holston has a nice population of quality Black Crappie that can be located on brush and fallen trees in the spring. It takes all of September, October and November to evacuate that water in a controlled manner, he said. These requirements will help keep the riverbed below the reservoir dam from . This abundance of public land makes South Holston a haven for campers and bank anglers. TVA Fishing Conditions for Mobile Devices. The reservoir has a flood-storage capacity of 252,800 acre-feet. If the water isnt released, it could increase flood chances, he added. chase koch wife; foreclosed properties quebec; if she'd had more self awareness grammar; bluepearl specialty and emergency pet hospital locations; best defensive tactics fm22 times to sight waterfowl, deer, and other wildlife. Then its back to the float-and-fly or jigging spoons when water temperatures start dropping. Construction on the dam began in 1942, stalled during World War II, but resumed in 1947 until its completion in 1950. Boone Lake Water Level Daily Levels By Month Holston River River Levels Boone Lake Forums Boone Lake Cameras WATER RESOURCE LINKS U.S. Drought Monitor TN Natural Resource Office The Drought Monitor focuses on broad-scale conditions. South Holston (TN VA)-16.51 2/28/2023 3:00 AM Tellico (TN) 808.06 813.00 -4.94 2/28/2023 3:00 AM . Here is the letter sent to the public from TVA: TVA manages the 652-mile Tennessee River and its many tributaries using a series of 49 dams to meet vital public needs in six key areas: navigation, flood damage reduction, energy production, water quality, water supply and recreation. South Holston plays a huge role for flood protection in the Tri-Cities.. Biologists are very concerned about the decline, and are considering all options to improve and restore the white bass fishery. In a year with normal rainfall, the water level in South Holston Reservoir varies about 25 feet from summer to winter to provide seasonal flood storage. Locals say that when the serviceberry and dogwood bloom, the white bass run. It is always best to call ahead and confirm specific pet policies before your stay. South Holston Dam is a hydroelectric facility. Waders will seldom find even waist deep water when not crossing the river. The width of the river can range anywhere from sixty yards to one hundred yards, and is easily crossable when the TVA isn't generating. Stern Hotel Soller - Traveller rating: 3.5/5. Flatheads are typically found where logs have collected to create a tangle of submerged and overhead cover. Numerous lodging options are available in and around the Abingdon area. The lakes shoreline habitats offer anglers a good diversity of structure including rock bluffs, shale banks and flat clay points. There is great night fishing with worms and lizards during the summer. Cherokee: The Cherokee watershed area will need approximately 5.5 inches of rain between now and June 1 for the lake to reach an elevation of 1,071 feet. dam began in 1942 but was halted in favor of other wartime construction Flatheads feed mostly on live prey, so anglers fishing artificial lures for bass or walleye often set the hook and find a huge flathead cruising for deeper water. Holston's Kitchen No Way Jose's 1836 W Andrew Johnson Hwy, Morristown, TN 37814 +1(423)616-0133 Some stations, for example, measure stage only. Because of this, South Holston Lake has risen to summer levels. Our center of publication and local coverage is the north Alabama region. Boating, fishing and water skiing are the most popular types of recreational activities on TVA-managed lakes. wilbur dam generation schedule. dmcgee@bristolnews.com | 276-645-2532 | Twitter: @DMcGeeBHC. The walleye runhas provided excellent fishing opportunities the last couple of years. River is home to an annual spring migration of white bass. Discharges are in cubic feet per second and are reported at the end of the hour. BRISTOL, Tenn. A handful of new businesses are coming soon to The Pinnacle. Use small flies tipped with minnows, small crankbaits, grubs, and spinners are recommended. TVA constantly monitors the weather to make predictions on how high the water level will go. 1 of 2. In fact, areas in northeast Tennessee that feed into the Holston River and the Clinch and Powell Rivers have only received 25-50% of normal rainfall this spring. Spawning sites are protected November through February. A 13-year-old boy in foster care loves baseball. If the TVA begins to generate, get out of the water. To access the Whittaker Hollow ramp take Exit 19 off I-81 and follow Route 58 east to Route 722, then follow signs directing you to the public boat-launching site. To help minimize the impact on the lakes, while still maintaining water supply and water quality, we are only releasing the minimum amount of water. The shoreline is only partially developed and much of the reservoir is bordered by the Cherokee National Forest. TVA to release minimal amounts of water at South Holston Dam due to record rainfall. Walleye abundance and size structure is very good. I have included more detailed information about each of the lakes below. Secondary points are also prime smallmouth holding spots during the spring. Were getting lakes prepared for heavy runoff season. Water depth during non-generating hours will remain low enough to wade 85% of the river. Largemouths typically dominate the electrofishing samples collected on the Virginia side of the reservoir each year. An eighteen-inch minimum size limit has been established for walleye in South Holston Reservoir. David Crigger/BHC Only a minimal amount of water is being released from South Holston Dam this week despite the continued rain.. Man died Wednesday. Change). This information is typically posted on a site's own website. hazards that can occur when boating, swimming, or fishing near dams. This lack of rainfall is impacting the ability for some lakes to reach their summer pool levels. Area Tennessee Valley Authority reservoirs, including Boone Lake, will begin the traditional late summer drawdown after Labor Day. There is a visitor center installation on-site to tell you more about the history of TVA and South Holston, and about TVAs current activities. During late May and early June look for bluegills on spawning beds in the backs of coves and on other shallow flats. South Holston Lake is a 7,580-acre impoundment operated by the Tennessee Valley Authority (TVA). Most of this offshore structure (flats, points, submerged islands) can be trolled more effectively than shoreline cover. Many anglers reported catching lots of small walleyes the past couple of years, and this is a good indication that great fishing might be just around the corner.

Autozone Bereavement Policy, Fannie Mae Heating Source Requirements, Articles T

tva south holston lake levels