SJRA Reducing Lake Conroe Release Rate

May 3, 2024 – As of 10 PM last night, the level of Lake Conroe had declined slightly for several hours. That indicates inflows are now less than outflows. Accordingly, San Jacinto River Authority Board Member Mark Micheletti worked out an agreement with the SJRA General Manager to start reducing the lake’s release rate.

By midnight the release rate was down from 69,585 cubic feet per second (CFS) to 64,797. And the lake level was down from 205.13 to 204.79.

This post contains information about the new release strategy, updated river and weather forecasts, plus a list of stunning rainfall totals from yesterday.

New Lake Conroe Release Strategy

During Harvey, many downstream residents felt the SJRA released too much for too long to return the lake to normal as quickly as possible.

The new agreement reached late tonight will have dam operators lowering the release rate in 2500 CFS increments. They will then wait two hours to see if the water level is increasing or decreasing, and adjust the next increment accordingly.

This strategy lets them delay additional decreases if necessary. For instance, if new heavy rainfalls increase inflows.

Dam operators still have the flexibility to release more if necessary. But it avoids leaving the release rate too high for too long when unnecessary.

All things considered, this strategy should protect downstream residents as much as possible. It also gives Lake Conroe operators a safety margin.

No Significant Changes to Flood Forecasts Since This Afternoon

As of 9:31 PM, Harris County Meteorologist Jeff Lindner had no changes to ongoing river forecasts. He emphasized that significant flood waves will continue moving down the East and West Forks of the San Jacinto into the weekend.

New Weather Forecast Reduces Rainfall Risk

Compared to yesterday’s weather forecast, however, Lindner also revised the expected overnight rainfall downward.

“Expect a mostly calm night with a low-end chance of a few showers toward morning. With heating on Friday and the approach of another thunderstorm complex from North Texas, there will be an increasing chance of rainfall during the day,” he said. “At this time. this complex of storms looks fairly progressive during the afternoon hours, but there is some uncertainty on how the storms evolve and how fast they cross the area.”

He says that additional rainfall amounts of 1-2 inches with slightly higher isolated totals can be expected on Friday. This additional rainfall is included in the river forecast models and should not greatly alter the current river forecast.

See river forecast summaries below.

East Fork San Jacinto River at New Caney (FM 1485)

Mandatory evacuation is still in effect for the eastern side of the river from FM 1485 to Lake Houston.

“Forecasted water levels will rise 7 feet higher than earlier this week. Structures on the ground will be flooded to rooftops levels,” says Lindner. “Elevated structures will be flooded. For reference, the forecasted water level is 4 ft below Harvey.” Similar to earlier this week, the rapid rise of several feet is expected late Friday into Saturday.

Impacted subdivisions: 
  • Idle Wilde
  • Idle Glen
  • Cypress Point
  • River Terrace
  • Magnolia Point
  • Northwood Country Ests
  • Low-lying eastern portions of Kingwood, such as:
    • Riverchase
    • Woodstream
    • Woodspring Forest
As of Thursday at 9 PM

West Fork San Jacinto River at Humble (US 59)

The river will rapidly rise from upstream inflows. It will reach major flood levels and peak near 62 ft on Saturday. Widespread low-land flooding will occur. It will likely impact lower areas in West Fork subdivisions such as:

  • Belleau Woods
  • Rivercrest
  • Northshore
  • Forest Cove 
  • Kings River Estates
  • Atascocita Shores
  • Kings Point
  • Kings Harbor
  • Kings River
  • Kingwood Greens
  • Fosters Mill
  • Kingwood Lakes
  • Barrington
  • Trailwood
  • Deer Ridge Estates

Kingwood residents should expect flooding of streets and structures near the East Fork, West Fork, and their tributaries.

Harris County is revising a potential inundation map that circulated Thursday on Facebook. Lindner says to expect the type of flooding we saw during the Memorial Days storm in 2016.

The following areas will be completely flooded with several feet of water: Deerwood Country Club, Deer Ridge Park, River Grove Park, Kingwood Country Club.

Elevated residents near the river should be prepared to be cut-off through the weekend if they don’t evacuate.

As of Thursday at 9 PM

West Fork of the San Jacinto River at I-45 

Major flooding is imminent upstream and downstream of I-45 including large portions of River Plantation and portions of Woodloch downstream to SH 242 and SH 99. Flows may approach the I-45 bridge deck. The current forecast is about 1 ft below Harvey recorded levels.

As of Thursday at 9 PM

San Jacinto River Below Lake Houston 

Major flooding is expected at all locations along the lower portions of the river.

Rio Villa will be completely inundated and cut-off and well as low lying in the river bottom around Highlands and HWY 90.

High velocity flows may damage vessels and barges near I-10 and result in loss of mooring.  

Flow may approach the I-10 river bridge west of the river crossing. Additionally, high flows will result in the suspension of Ferry service.

As of Thursday at 9 PM

Spring Creek

According to Lindner, the creek is rising on the upper end due to flows from Waller and Montgomery Counties. Minor flooding is in progress along the upper portions of Spring Creek at Hegar Rd. Water levels along the creek are high, but any flooding is minor and to rural areas near the creek. 

Willow Creek 

Willow Creek has crested and is slowly falling.

Yesterday’s Storm: Gage Readings

The storm that swept through southern Montgomery and northern Harris Counties yesterday dropped impressive amounts of rainfall.

Harris County Flood Control District released the following totals at 7 PM Thursday.

  • 8.24 in. – 1050 Spring Creek @ I-45
  • 8.2 in. – 1320 Willow Creek @ Kuykendahl Road
  • 7.76 in. – 755 San Jacinto River @ Lake Houston Pkwy
  • 7.2 in. – 785 Peach Creek @ FM 2090
  • 7.12 in. – 790 East Fork San Jacinto @ FM 1485
  • 6.92 in. – 795 East Fork San Jacinto @ FM 2090
  • 6.8 in. – 765 San Jacinto River @ SH 99
  • 6.64 in. – 1745 Cedar Bayou @ FM 1960
  • 6.6 in. – 1960 Luce Bayou @ SH 321
  • 6.12 in. – 770 San Jacinto River @ SH 242
  • 5.88 in. – 780 Caney Creek @ FM 2090
  • 5.76 in. – 1040 Spring Creek @ FM 2978
  • 5.64 in. – 1940 Luce Bayou @ FM 2100
  • 5.48 in. – 1340 Willow Creek @ SH 249
  • 5.12 in. – 1056 Mill Creek @ FM 1774
  • 5.04 in. – 1950 Luce Bayou @ SH 99
  • 5.0 in. – 1080 Spring Creek @ Decker Prairie-Rosehill Road
  • 4.96 in. – 760 San Jacinto River @ US 59

Locations Out of Banks, Flooding Likely

    HCFCD also reported that the following streams/channels were out of their banks and flooding was likely.

    • 710    San Jacinto River @ Rio Villa
    • 720    San Jacinto River @ US 90
    • 740    Lake Houston @ FM 1960
    • 760    San Jacinto River @ US 59
    • 780    Caney Creek @ FM 2090
    • 785    Peach Creek @ FM 2090
    • 790    East Fork San Jacinto @ FM 1485
    • 795    East Fork San Jacinto @ FM 2090
    • 1054    Mill Creek @ FM 1486
    • 1074    Walnut Creek @ Joseph Road
    • 1084    Threemile Creek @ Joseph Road
    • 1090    Spring Creek @ Hegar Road
    • 1195    Mound Creek @ FM 362
    • 1950    Luce Bayou @ SH 99

    Flooding Possible

    The following streams were still in banks, but flooding was possible.

    • 755    San Jacinto River @ Lake Houston Pkwy
    • 765    San Jacinto River @ SH 99
    • 770    San Jacinto River @ SH 242
    • 796    East Fork San Jacinto @ SH 105
    • 1050    Spring Creek @ I-45
    • 1055    Bear Branch @ Kuykendahl
    • 1076    Birch Creek @ Riley Road
    • 1086    Threemile Creek @ FM 362
    • 1110    Cypress Creek @ Cypresswood Drive
    • 1186    Live Oak Creek @ Penick Road
    • 1190    Little Mound Creek @ Mathis Road
    • 1320    Willow Creek @ Kuykendahl Road
    • 1340    Willow Creek @ SH 249
    • 1740    Cedar Bayou @ US 90
    • 1745    Cedar Bayou @ FM 1960
    • 1960    Luce Bayou @ SH 321
    • 2200    Houston Ship Channel @ Juan Seguin Park

    Resources for More Information

    To see:

    If in doubt about whether you will flood, remember. Better safe than sorry. If you evacuate needlessly, the most you lose is a day or two. But if you don’t and you flood, you could lose everything.

    Posted by Bob Rehak on 5/3/24

    2439 Days since Hurricane Harvey

    Lake Conroe Release Rate at 90% of Harvey

    5/2/24 at 4:30 PM – The San Jacinto River Authority (SJRA) is releasing water at the rate of 69,545 cubic feet per second (CFS from Lake Conroe. That’s down a couple thousand from the 71,835 they released earlier this afternoon, the second highest release rate ever – 90% of the all-time record of 79,000 CFS during Hurricane Harvey.

    At that rate, NOAA predicted the San Jacinto West Fork at US59 would peak at 62.4 feet. Since then, they’ve reduced that back a bit to 62.2.

    However, the level of Lake Conroe is still rising slightly. It stands at 205.13 MSL (mean feet above sea level) as of 4:30 PM.

    And local leaders including Houston Mayor John Whitmire, State Rep. Charles Cunningham and City Council Member Fred Flickinger met in Kingwood to plan emergency response with first-responders.

    More Rain on Way

    The level of Lake Conroe is up significantly since this morning. And another rain storm is headed our way tonight. The National Weather Service predicts a 40% chance of more thunderstorms tonight. Anything that falls will be on top of almost 7 inches of rain received in the Kingwood area earlier today.

    Flood watches and warnings remain in effect at the present time. Any new rain will fall onto already saturated soils, resulting in rapid runoff.

    SJRA Pushing Up Against Limit

    But the SJRA is running out of room. At 207, they flood Lake Conroe homes and endanger the dam, according to Mark Micheletti, an SJRA board member who lives in Kingwood.

    Micheletti has demanded that SJRA operators throttle back releases as soon as they stabilize the Lake Conroe’s level. The SJRA hopes to keep a safety margin by not letting the lake level get above 206, but nature, not engineers will make that call.

    Meanwhile, the uncertainty has many Kingwood people in panic mode wondering whether they should evacuate. I’ve been deluged (pardon the pun) with requests for information.

    Whitmire Visits Kingwood to Plan Flood Response

    Houston Mayor John Whitmire came to Kingwood this afternoon to meet with first responders and area leaders. He wanted to personally see the situation and assess what the area needs. He met with Fire Chief Samuel Peña, first responders, State Representative Charles Cunningham and City Council Member Fred Flickinger at Fire Station 102 on West Lake Houston Parkway.

    CM Fred Flickinger (center) met with Mayor Whitmire (right), Chief Samuel Peña (left) and other first responders at Fire Station 102 this afternoon on West Lake Houston Parkway.

    Peña emphasized the need for vehicles to stay out of high water. The fire department had already made numerous high water rescues today.

    State Representative Charles Cunningham (left) also helped plan the emergency response.

    At the meeting, Whitmire also said that he had discussed evacuation orders for certain subdivisions with Harris County Judge Lina Hidalgo. After Harvey, “communication with residents” and “warning time” were identified as two of the primary things officials needed to improve.

    Current East Fork Predictions and Evacuation Orders

    According to Harris County Meteorologist Jeff Lindner, the County has issued evacuation orders for the east side of the East Fork San Jacinto from FM1485 to Lake Houston. (Lake Houston Park is on the west side.) Forecasted water levels will rise 7-8 feet higher than earlier this week. Structures on the ground will be flooded to rooftop levels. Elevated structures will be flooded.

    For reference, the forecasted East Fork water level is 3 ft below Harvey.

    Impacted subdivisions: 
    • Idle Wilde
    • Idle Glen
    • Cypress Point
    • River Terrace
    • Magnolia Point
    • Northwood Country Estates

    Current West Fork San Jacinto Predictions and Warnings

    The West Fork is rapidly rising from upstream inflows. It will reach major flood levels and will rise to near 62 ft on Saturday. Widespread low-land flooding will occur impacting the following subdivisions:

    • Belleau Woods
    • Rivercrest
    • Northshore
    • Forest Cove
    • Kings Point
    • Atasocita Shores

    In Kingwood, Lindner expects flooding of streets and the lowest structures nearest the river. He also predicts backwater impacts along the tributaries. That means high river levels could force water in channels and tributaries to back up.

    The following areas will be completely flooded with several feet of water: Deerwood Country Club, Deer Ridge Park, and Kingwood Country Club.

    Elevated residents near the river should be prepared to be cut-off through the weekend.

    I have queried HCFCD about the list of subdivisions above. It seems incomplete. But I have not yet heard back.

    San Jacinto River Below Lake Houston

    Major flooding is expected at all locations along the lower portions of the river.

    Rio Villa will be completely inundated and cut-off. 

    High velocity flows may damage vessels and barges near I-10.

    Flow may approach and potentially reach I-10 on the west side of the river.

    Real Time Inundation Monitoring

    To monitor what’s going on around you, Harris County Meteorologist Jeff Lindner suggests using the Real-Time Inundation Mapping Tool found in the Harris County Flood Warning System. From the home page, just click “Inundation Map” in the upper left tool bar, then zoom into the area of interest.

    As of 4:22 PM on 5/2/24. Note large areas already inundated.

    Easy Way to Find the Elevation of Your Home

    Don’t know the elevation of your home? Consult this post about how to find it in the USGS National Map.

    More updates later. SJRA may issue another statement at 8PM.

    Posted by Bob Rehak at 4:30 PM, Thursday, May 2, 2024

    2438 Days since Hurricane Harvey

    Lake Conroe Increasing Release Rate After Torrential Rain

    5/2/24 Noon Update: Since publishing this, Lake Conroe has continued to rise and the SJRA has increased the release rate to 66,100 CFS. – Heavy storms dumped 10-12 inches of rain in isolated areas north of Lake Conroe last night. Most areas experienced 5-7 inches. As a result, Lake Conroe has increased its release rate to 60,455 cubic feet per second and it could go higher.

    The area north of Lake Conroe has received more than 17 inches in the last week.

    Engineers are currently modeling several different scenarios. The current inflow is more than two times greater than the outflow. The current release rate is already the second highest in the history of Lake Conroe.

    Source: SJRA as of 10:00 AM 5.2.24.

    Current Situation

    According to Jeff Lindner, Harris County meteorologist, significant flash flooding is ongoing from north of HWY 105 to southern Montgomery County and the northern portions of Harris County.

    At 8:27 am, radar showed the storm had moved into northern Harris, and northern Liberty Counties.

    RadarScope Pro Screen Capture at 8:23 AM, 5.2.24, Orange indicates 5″.

    It dumped 6 inches of rain in my gauge in two hours. And the total is still climbing.

    Such high hourly rainfall rates result in street flooding. Lindner warned people not to travel unless absolutely necessary.

    According to Lindner, “There may be a break in the activity in the afternoon hours before another complex of storms arrives overnight into Friday morning with additional heavy rainfall. But confidence in the forecast is not high.”

    Impact of Rains

    “Significant rainfall has also occurred over the headwaters of the East Fork of the San Jacinto River. New flood waves will certainly be generated on both the East and West Forks of the San Jacinto River,” Lindner added. The same holds true for Lake Livingston and the Trinity River.

    The heavy runoff over already saturated grounds will migrate downstream Friday into the weekend. 

    The SJRA does not have a dam on the East Fork and can’t control it. Dam releases on the West Fork do not impact the East Fork, but do impact Lake Houston.

    Lake Conroe Release Rate Increasing, Max Uncertain

    Lake Conroe virtually quadrupled its release rate from 17,000 cubic feet per second (CFS) at 7 AM to 60,455 CFS at 9:45 AM.

    The lake level at 10:48 AM had reached 204.4 – 3.4 feet above normal.

    Mark Micheletti, San Jacinto River Authority (SJRA) board member, said that SJRA engineers are modeling several release scenarios. So the ultimate release rate is uncertain as of this writing.

    The flowage easement at Lake Conroe is 207. That’s the elevation at which homes start to flood.

    Some people will criticize the SJRA for not releasing more water sooner. However, it was not an easy call.

    Lake Houston was already flooding from the East Fork. And a massive release coming down the West Fork could have flooded homes.

    Micheletti added, “Hydrographs are useless in a situation like this because you don’t yet know what the release will be,” he added.

    During Harvey, the SJRA released 79,000 CFS. So, they are already at 75 percent of the devastating Harvey release rate.

    But even with that, the current release rate is only about one third of the estimated water coming into the lake. “So that’s our challenge,” said Micheletti. The release rate will almost certainly go higher.”

    The Harris County Flood Warning system showed that the San Jacinto West Fork is still within banks, but that likely won’t last long.

    Before the heavy rains moved south this morning, river gages on the East and West Forks were dropping slowly as floodwaters receded from earlier in the week. But we’re about to experience a second wave there.

    If you’re in a place that has flooded before, the safest course of action is to start developing an action plan now.

    River Predictions

    At 10 AM, Lindner released new hydrographs for the West Fork, East Fork, and the area below Lake Houston.

    West Fork

    As of 10 AM, 5.2.24

    A rise to flood stage will occur today with a rise above major flood levels on Friday. Widespread low land flooding near the river is expected. The forecast may need to be increased more because of the uncertainty over Lake Conroe releases.

    While there will be widespread low land flooding, the lowest structures in Kingwood are not impacted until over 60-62ft. Expect this level of water in the river to create backwater in tributaries that could lead to additional flooding.

    A reader sent in this photo of the new Northpark South development between the West Fork and Sorters-McClellan Road.

    NorthPark South already underwater from rains. 5.2.24 at 11 AM. Photo by Jody Binnion.

    East Fork

    A significant rise on the East Fork is expected as the upstream flood wave moves downstream. Forecasted water levels will reach 6-8 ft higher than earlier this week. This expected flood level will be higher than TS Imelda and will be similar to October 1994. Even elevated structures may be flooded, according to Lindner.

    Below Lake Houston

    Other Flooding

    As I write this, I have received word that Taylor Gully is flooding and parts of nearby streets are closed.

    White Oak Creek is also flooding. Royal Pines, the new development on White Oak at the northern end of West Lake Houston Parkway, has also flooded neighbors’ yards and a garage.

    Flash flooding is ongoing along Willow and Spring Creeks, which are rising rapidly. Flooding along these creeks is becoming likely. Widespread street flooding and some structure flooding is possible.

    A training band of thunderstorms will produce another 2-4 inches of rainfall on top of the already 4-6 inches that has fallen in these watersheds.

    Pardon the pun, but the situation is very fluid. Sometimes new information comes in faster than I can update it.

    I will post updates including photos when the rain lets up.

    Posted by Bob Rehak at 10:00 AM on 5/2/24

    2438 Days since Hurricane Harvey

    East Fork Homes Flooding, Another Flood Watch Issued

    May 1, 2024 – Even as East Fork homes are flooding, the National Weather Service has issued another Flood Watch for the region.

    Monday’s Storm Brings Wednesday’s Flood

    The stormwater from last Sunday night/Monday morning that’s flooding homes near the East Fork San Jacinto could get reinforcements tonight. Another powerful storm is approaching and will collide with moisture laden air from the Gulf later day.

    That caused the National Weather Service to issue another flood watch from 10 PM this evening until Thursday evening for Houston and Harris County.

    That same NWS bulletin also says that a flood warning remains in effect for the East Fork San Jacinto near New Caney affecting Liberty, Montgomery and Harris Counties.

    Jeff Lindner, Harris County’s meteorologist, warned in his midday report that “Widespread amounts of 2-5 inches are likely with isolated totals of 6-9 inches. High hourly rainfall rates will be likely on the order of 2-4 inches which will produce rapid onset flash flooding.”

    Lake Conroe and Lake Livingston Already Taxed to Max

    The additional rainfall could overburden already overtaxed watersheds. “There is no capacity at either Lake Livingston or Lake Conroe,” said Lindner. “Additional inflows and run-off will have to pass through the dams’ floodgates.”

    Although Lindner expects the heaviest rains to stay north of Harris County, “There is some potential that some of the heavy rainfall reaches into northern Harris County overnight,” he added.

    If so, the storm could impact Spring, Cypress, Little Cypress, and Willow Creeks as well as the tributaries in northern Waller and southwestern Montgomery Counties, such as Lake Creek.

    Lindner says significant rises will be possible depending on the rainfall amounts and patterns. Flash flooding will be likely where heavy rains occur.

    That could deal a devastating blow to homes already flooding along the East Fork.

    East Fork Photos Taken Morning of Mayday Flood

    Pictures taken this morning between 9 and noon showed roads flooded out and many homes and vehicles already underwater.

    TXDoT closed FM1485 at the East Fork/Montgomery County line.
    SH99 on left, FM1485 on right.

    Streets close to the river also flooded.

    Looking S. Casey Road on left flooding from East Fork on right.
    Home with flooded vehicles and heavy equipment at Casey and Spaulding.
    Flooded homes at Casey and Green.
    Cypress Hollow just N of SH99.

    I took more than a hundred photos like these this morning. Some people were lucky with the water stopping just feet from their homes. Other people were not so lucky. They will need help.

    Colony Ridge, Plum Grove and FM2090

    Farther north, I explored Colony Ridge and Plum Grove near FM2090.

    One of the main entrances to Colony Ridge where it approaches Plum Grove Road

    The water there was already starting to recede. But still, many roads were barely passable. Most smaller vehicles did not brave the water.

    Opposite angle, same intersection. Unable to see the sides of the road, traffic tried to stay close to the centerline to stay out of the ditches.
    Looking NW over East Fork. FM2090 was still passable, but water lapped at the bottom of the bridge. The East Fork completely flooded the abandoned sand mine (upper right) and swept sediment out of mine.

    Ironically, even though I could see my way out of Colony Ridge (from the air), I could not get to FM2090 on the ground because of floodwaters. I had to drive south to SH99 to return home.

    Dunnam Road Boat Launch

    Back in Kingwood, I called a friend on Dunnam Road. She said her boat launch flooded and that water was lapping at the first house coming up the hill.

    Dunnam Road boat launch.
    Note water surrounding house adjacent to boat dock. Luckily it did not flood and water is receding as of 4PM.
    This young man appeared to be making the most of the flood by giving his daughter a fishing lesson. A neighbor told me he’s been doing that since she was born!

    Posted by Bob Rehak on May 1, 2024

    2437 Days since Hurricane Harvey

    East Fork Predicted to Rise 15 Feet in Next 24 Hours

    (Updated with more Subdivisions/Streets at 9PM Tuesday) As yesterday’s heavy rains work their way downstream, the National Weather Service’s (NWS) Advanced Hydrologic Prediction Service forecasts that the East Fork at FM1485 will rise 15 feet in the next 24 hours.

    As of noon Tuesday, NWS said the river had already reached the “Action Stage” at 56.85 feet. NWS predicts it will reach 71.9 feet by tomorrow at noon. “Major flooding” at that location begins at 69 feet.

    From NWS Advanced Hydrologic Prediction Service at noon on 4/30/24

    Jeff Lindner, Harris County’s meteorologist, says, “Many of the structures in this area have been elevated, however isolated homes that remain on the ground will be subject to flooding at these levels.”

    “Flooding similar to TS Imelda in 2019 is expected.”

    Jeff Lindner, Harris County Meteorologist

    FM1485 will be under several feet of water. Flows may even approach the deck of the Highway 99 bridge!

    Subdivisions and Streets that Could Be Affected

    Lindner specifically warned about flooding that could affect the following subdivisions and streets.

    Magnolia Point (West end of Commons of Lake Houston)
    • Opal Way
    • Diamond
    • Mendencino
    • Lassen Villa
    • Glen
    • Magnolia
    • Hill
    • Calvins
    • Collins
    • Calaveras Creek

    Flooding of streets is likely. Elevated homes will be cut-offSome structure flooding is possible for any homes on the ground in this area.

    South of FM 1485 (east side of the river): 
    • Spalding
    • Green
    • Jett
    • Casey

    Some structure flooding is possible for any homes on the ground in this area.  

    Idle Glen subdivision: 
    • Brookside
    • Chinquapin
    • River Side
    • E. San Jacinto
    • Glenwood
    • Dipping
    • Idlewild
    • Lazy Creek

    Almost all of the homes in this area are elevated, but will be cut-off. Any homes on the ground will be flooded.

    Northwood Country Estates: 
    • Flooding of streets is likely. Elevated homes will be cut-off.
    • Disher
    • Bounds
    • Thomas
    • Davidson
    • A new 553-acre Friendswood development called Sila is in this area.
    River Terrace: 
    • Flooding of the following streets is likely. Elevated homes will be cut-off.
    • River Terrace
    • Elm
    • Pine
    • Cherry Laurel
    • Holly 
    • Cypress 
    Cypress Point:
    • The following streets will be flooded (closest to the river). Elevated homes will be cut-off.
    • Blue Lake
    • Oak Knoll
    • Wild Oak
    • Birchwood

    The East Fork should also rise 10-15 feet at FM2090.

    East Fork at Cleveland

    Farther upstream at Cleveland, the East Fork has already peaked and is beginning to recede after only reaching a moderate level of flooding.

    As of noon 4/30/24, the East Fork at Cleveland was at a moderate flood stage.

    Structure Flooding In Kingwood NOT Expected

    Lindner added that, “Flooding will occur in the low lying areas of Kingwood that back up to the East Fork of the San Jacinto River. This is mostly all non-developed lands near the river or back yards with bulkhead that front the river. Structure flooding is NOT expected in Kingwood.”

    Meanwhile, at as of noon on 4/30/24, NWS predicts the West Fork will not flood.

    Noon, 4/30/24

    View Real-Time Inundation Mapping

    To view Real-Time Inundation Mapping, go to www.harriscountyfws.org and click “inundation map” on the left side.

    Trinity River Also Flooding Badly

    The Trinity River at Liberty is about to see major flooding through Sunday. The Trinity is a separate watershed. It will not affect Harris County.

    As of noon, 4/30/2024

    Other Flooding

    Fourteen gages show various streams and creeks in the region are at or near flood stage.

    To see gage levels and predictions for a stream near you, go to the NWS Advanced Hydrologic Prediction Service.

    The Harris County Flood Warning System offers many of the same features plus more, such as historical flood heights.

    Posted by Bob Rehak on 4/30/24 at 2PM

    2436 Days since Hurricane Harvey

    Storm Report: Flooding Delayed Because of Rainfall Distribution

    4/29/24 – The rainfall distribution in last night’s storm was very uneven. It ranged from a tenth of an inch in some places to more than 10 inches in others.

    Totals to the north and east of Houston approached 8-10 inches in places. But most of Harris County received less than 2 inches.

    Regardless, the heaviest rainfall in the upper reaches of the East Fork San Jacinto watershed will migrate downstream in the next 2-3 days and cause flooding in low-lying areas near New Caney. The West Fork should only be moderately affected.

    After three hours of driving around this morning, all ditches and minor streams that I saw appeared to be within their banks.

    Very Uneven Rainfall Distribution

    The farther north and east you went, rainfall increased. The gage at US59 and the West Fork received only 1.76 inches.

    My rain gage by Kingwood High School recorded 3.11 inches. And a friend who lives by the Montgomery County line recorded a little more than 4 inches.

    The Trinity River Authority recorded 10.92 inches on Caney Creek at a small town called Fryday north of Lake Livingston. That gage recorded a whopping 6 inches in one hour between 8 and 9 PM last night.

    A gage in Mont Belvieu recorded almost 9 inches. Almost 5 inches of that fell in one hour between 2 and 3 AM.

    Most of the higher totals occurred in watersheds that will not drain directly into Harris County. At 1PM on Monday, only six gages in and around the county showed danger signals (meaning a stream was in danger of coming out of its banks).

    Most Streams in Banks

    The good news: Only one stream at this hour is in danger of coming out of its banks upstream from Lake Houston. That’s Peach Creek near 2090. Peach Creek forms the western boundary of Lake Houston Park.

    From Harris County Flood Warning System as of noon 4.29.24.
    From Harris County Flood Warning System as of noon 4.29.24.

    The bad news: SJRA is releasing almost 10,800 cubic feet per second from Lake Conroe at noon due to heavy rains north of the lake.

    From SJRA.net at noon 2.29.24
    Rainfall totals north of Lake Conroe and around Lake Livingston. From Harris County Flood Warning System, noon 4.29.24.

    Farther south, however, totals dropped off rapidly. Parts of western and southern Harris received only a tenth of an inch!

    From Harris County Flood Warning System as of 1PM 4/29/24

    Flood Forecasts

    Because of the rainfall distribution, you need to look upstream from where you are to see whether your area is in danger of flooding. You also need to factor in travel time for the floodwaters. Due to the distance of the heaviest rainfall, flood impacts will be delayed.

    Lake Houston

    Inflows from the East Fork, Peach and Caney Creeks, and Luce Bayou will result in a rise in the lake level Tuesday into Thursday. Elevated water levels and flows will be likely through Lake Houston for much of this week, according to Jeff Lindner, Harris County Meteorologist.

    West Fork San Jacinto

    Lindner expects no flooding at this time…again due to the very uneven rainfall distribution.

    Much of the rainfall overnight fell above (north) of Lake Conroe. That will buffer some of this inflow. Additionally heavy rainfall largely missed Spring and Cypress Creeks and only modest amounts occurred along middle and upper Lake Creek. So, additional inflows below Lake Conroe look to be minimal.

    The river is not expected to reach flood stage at US 59. However, you should continue to monitor the situation for any changes.

    This morning, the West Fork was up slightly. Large amounts of foam and debris were moving downstream. But even low-lying areas such as River Grove Park and the area under the US59 bridge were well above water.

    River Grove Park Boat Dock area, around 10AM on 4.29.24
    West Fork at US59 looking S toward Houston. At 10AM, the river was still well within its banks.

    That could change by tomorrow morning.

    Worst Flooding Will Be on East Fork at New Caney

    A significant rise in the East Fork will start on Tuesday into Wednesday. The river will rise just below major flood level later this week.

    At the forecasted levels, FM 1485 will be impassable on the west approaches and several roads downstream of FM 1485 will become flooded and impassable on the west side of the channel. Additionally low lying areas along the river in River Terrace will experience high water, according to Lindner.

    Stay tuned for more updates tomorrow and Wednesday.

    Posted by Bob Rehak on 4/29/24 based on information provided by Harris County Meteorologist Jeff Lindner

    2435 Days since Hurricane Harvey

    Breach at Hallett Mine Expanding

    Correction: This sand pit in this post was sold by Hallett to Riverwalk Porter LLC on January 23, 2024.

    A breach at the giant Hallett Mine on the San Jacinto West Fork that began in late January or early February is still open and expanding.

    Two Pairs of Pictures, Two Weeks Apart

    I first reported the breach on April 10. Below are pictures taken then and today.

    Hallett Breach, April 10, 2024
    Hallett Breach, April 24, 2024

    In the pictures above, note the difference in the river bank on the left. It appears much more eroded. Also note the freestanding tree in the water on the right in the second photo that is not visible in the first.

    Comparison of these wider shots shows more differences.

    Hallett Breach, April 10, 2024
    Hallett Breach, 4/28/2024.

    The first shots in each pair were taken when the water was up due to heavy rains upstream. The second shots were taken when the river was at its normal level (57 feet at SH99 as opposed to 66 feet).

    In the shot immediately above, note the lack of vegetation on the sidewalls of the pond. That’s one indication that the height of water in this pond was much higher at one time.

    Google Earth Image

    This image from Google Earth shows water draining out of the pond on February 19.

    Hallett Breach
    Hallett Breach in satellite image from Google Earth taken on 2/19/2024 shows silty water pouring out of the mine.

    Impacts on River

    One boater I interviewed for this post last Wednesday when SJRA was releasing 530 cubic feet per second from Lake Conroe said he could normally get all the way to Conroe in his flat bottomed boat at that flow rate. But on that day, he was frequently hitting bottom.

    This is consistent with the experience of boaters launching farther downstream in River Grove Park. There, the river depth is now just 1-2 feet in places. And that’s after it was dredged just four years ago.

    The Kingwood Service Association is studying ways to keep its boat launch open. But the need for dredging is becoming more expensive and frequent.

    I should add in fairness that the river creates a fair amount of erosion on its own and that Hallett isn’t the only mine on the West Fork with breaches in its dikes.

    It is, however, the largest mine by far and has a history of dumping its waste into the West Fork. Searching on the keyword “Hallett” in this website reveals 30 posts that include references to the controversial mine.

    It has now been approximately three months since the breach.

    Posted by Bob Rehak on 4/28/2024

    2434 Days since Hurricane Harvey

    The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.

    Recommended Changes in New MoCo Drainage Criteria Manual

    In 2019, Montgomery County posted a minor update to a drainage criteria manual first published in 1989. However, in February 2024, the County published a draft of a comprehensive new update to the county’s drainage standards. The 124-page manual is a thorough rewrite that brings the County’s standards up to date and more in line with surrounding areas.

    Some Major Revisions

    Because the manual is targeted to engineers, it gets very complex very fast. However, it is obvious that Montgomery County took pains to remedy some of the shortcomings of the past. For instance:

    Section 1.4

    Addresses approved hydraulic modeling software packages. It’s not that the packages are revolutionary. It’s that it requires the use of industry-standard packages. The previous manual did not; it only recommended certain packages. According to one flood plain manager I talked to, this will greatly facilitate the checking of plans. (See Page 10.)

    Section 1.5

    Specifies “No Adverse Impact” from drainage. The County says, “…one property owner should not be allowed to adversely affect the rights of other members of the community.” This protects the rights of neighboring property owners and also protects the natural systems that provide flood mitigation benefits to the community. It specifically prohibits flooding of downstream neighbors.

    Significantly, No Adverse Impact includes impacts other than water surface elevation. They include peak flow, velocity and flow type. (See Page 11.)

    Section 2.2.1

    Mandates use of certain roughness coefficients for use in different situations. This affects calculations for the speed of runoff. They are critical for determining how fast and high flood peaks will build. In the old manual, calculating the roughness was somewhat subjective. (See pages 16, 48 and 50.)

    Section 3.3

    Unifies the discussion of erosion controls (both structural and natural) in great detail.

    Section 5.3

    Requires more storm drain inlets along roads by reducing spacing to 500 feet from 750.

    Section 5.4

    Requires land plan and street layout changes to improve stormwater conveyance in 100-year events.

    Section 6.2

    Stipulates that all projects shall mitigate and attenuate the runoff for 5-, 10- and 100-year storm events.

    Section 6.3

    Requires detention for all proposed developments, regardless of size. It also specifies how the amount will be calculated, and minimum rates (acre feet per acre) for different sizes and types of developments. In addition to other things, it specifies that post-development runoff rates shall not exceed pre-development rates.

    Section 7.2

    Discusses acceptable floodplain mitigation measures. For instance, “Natural channel clearing to reduce friction losses within the floodplain shall not be allowed as an acceptable floodplain mitigation measure.”

    Maintenance

    The name and contact information for the entity responsible for maintenance of detention facility, channels, and storm sewers must be listed on construction drawings under the proposed guidelines. “Maintenance shall be the responsibility of the private property owner and not the County,” says the draft manual in various sections.

    Still Doesn’t Completely Embrace Harris County Recommendations

    From a public protection standpoint, the changes in the new drainage criteria manual may not be revolutionary, but they are a vast improvement according to several hydrologists and a flood forecaster I consulted.

    Does it incorporate the minimum drainage standards that Harris County urged surrounding counties to adopt after Hurricane Harvey? Some, but not all of them.

    The table below summarizes Harris County’s recommendations and the recommendations reflected in Montgomery County’s draft drainage criteria manual.

    Comparison of Recommendations
    MeasureHarris Montgomery 
    Use of Atlas 14 Rainfall StandardsYesYes
    Minimum Detention Rate.65 acre feet/acre.55 acre feet/acre
    Prohibit Hydrographic TimingYesYes
    No Net Fill in 500-Yr FloodplainProhibitedStill allowed
    Finished Floor ElevationAt 500-yr flood elevation100-yr flood elevation + 1 ft.


    Atlas 14, Minimum Detention Rates, Hydrologic Timing

    Montgomery County already uses Atlas 14 rainfall rates as the basis for all its drainage calculations. That will continue if the new draft drainage criteria are adopted. That’s great.

    Even better though is this news. With a few minor exceptions, Montgomery County will require a minimum detention rate of .55 acre-feet per acre. It’s not quite up to Harris County rates, but it’s WAAAAAY better than nothing.

    Previously, many developments used hydrographic timing surveys to avoid building any stormwater detention at all. But if adopted, the new drainage criteria will prohibit the use of such surveys. They will require detention for all new developments.

    Timing surveys encouraged developers to get their water to bayous as fast as they could, which built flood peaks faster and higher for people downstream.

    Fill, Finished-Floor Elevations

    Sadly, Montgomery County’s draft drainage criteria would allow fill to be brought into the 500-year flood plain. In extreme events, this could constrict the width of the floodplain and cause a rise in flood levels.

    The proposed finished-floor-elevation requirements in MoCo are also less stringent than Harris County. That, however, is the sort of thing more likely to affect Montgomery County residents than those downstream.

    I remember owning a new home in the Dallas area back in the early 1980s that was supposed to be 1-foot above the 100-year flood plain. Within three years, it flooded. A new survey by the Army Corps of Engineers found that because of insufficiently mitigated upstream development during those three years, we were actually ten feet below the 100-year floodplain instead of a foot above it.

    Montgomery County is also revising its subdivision regulations. They may have more to say on this topic.

    Complete Manuals and Summary of Drainage Revisions

    To see the old and proposed new drainage criteria manuals, see these links:

    Also see Montgomery County’s Summary of the Revisions.

    For easy future reference, you can also find these documents under the Regulations tab in the reports page.

    As of this writing, it is not clear when the new manual will go before Commissioners Court for approval.

    Posted by Bob Rehak on 4/27/24

    2433 Days since Hurricane Harvey

    For the more technically inclined, Montgomery County provided this summary of significant revisions.

    Area Leaders Meet with GLO Commissioner Buckingham

    Harris County and the Houston area are receiving $863 million from the U.S. Department of Housing and Urban Development (HUD) via the Texas General Land Office (GLO) for disaster relief and flood mitigation. So, on Thursday, April 25, 2024, GLO Commissioner Dr. Dawn Buckingham met with a group of Lake-Houston-Area leaders to discuss the area’s flood mitigation needs.

    The meeting, arranged by State Representative Charles Cunningham, also included Director Tina Petersen of the Harris County Flood Control District (HCFCD); Director Thao Costis of Harris County Community Services (CSD); Humble Mayor Norman Funderburk; and Dustin Hodges, Chief of Staff for City of Houston Council Member Fred Flickinger.

    (L to R) Dustin Hodges; Tina Petersen; Thao Costis; Dr. Dawn Buckingham; Rep. Charles Cunningham; Norman Funderburk; Alice Rekeweg;  Scott Elmer, HCFCD; and Kathleen Jordan.

    Projects Vie for Funding

    As reported on 4/23, Buckingham was in Houston to discuss Disaster Relief and Mitigation projects totaling $863 million. But there are more deserving projects than money to fund them all. So Buckingham, her team, HCFCD and CSD met with area leaders to discuss needs.

    The GLO administers the distribution of HUD funds in Texas. Among Lake Houston Area projects discussed for funding were:

    • Taylor Gully Channel Improvements ($25.5 Million)
    • Woodridge Stormwater Detention Basin – Compartment 1 ($13.3 Million)
    • Woodridge Stormwater Detention Basin – Compartment 2 ($17.5 Million)
    • Mercer Park Drainage Improvements ($5.3 Million)
    • Mercer Detention Basin ($15.4 Million)
    • Mercer Botanic Garden Restroom Improvements (0.6 Million)
    • New Humble Fire Station ($4.5 Million)

    No commitments were made at the meeting, but the mood was positive and everyone left smiling.

    Buckingham is still collecting information. She listened attentively, asked probing questions and left with a better understanding of the area’s needs.

    Splitting the Woodridge Basin into two phases helps ensure that at least one compartment will get funded and provide enough mitigation to let the Taylor Gully Channel Improvements move forward.

    Other Topics

    Several other topics came up toward the end of the hour-long meeting. They included sedimentation, dredging, and the need for sand to nourish beaches along the Texas coast. The GLO needs sand to replace eroding beaches…and this area needs to remove sand collecting in streams and Lake Houston.

    That raised the tantalizing possibility of collaboration for mutual benefit and solving two problems at once.

    More news to follow.

    Posted by Bob Rehak on 4/26/24

    2432 Days since Hurricane Harvey

    Ramsey Hosting Infrastructure Meeting at KHS Tonight

    Harris County Precinct 3 Commissioner Tom Ramsey’s Office will host a meeting about local infrastructure at Kingwood High School tonight. The meeting will include representatives from the City of Houston, San Jacinto River Authority, Congressman Dan Crenshaw’s office, and Harris County Flood Control District.

    6:30-8:00 PM

    The infrastructure meeting will follow an open-house format. After brief remarks, residents will be free to mingle with representatives from the various organizations at tables set up throughout the room. So you can come and go as you please.

    This will give everyone a chance to discuss issues in depth. See details below.

    Focus on Infrastructure

    Infrastructure covers a lot of territory. Drainage. Roads. Parks. Water. And more.

    Ever wonder:

    • What’s holding up those new floodgates on the Lake Houston Dam?
    • Whether seasonal lowering of Lake Conroe will return if this turns out to be the hurricane season everyone is predicting?
    • What is really being done to reduce flood risk in this area?
    • When will Edgewater Park become a park?
    • Are mitigation efforts keeping us ahead of upstream development?
    • Can the SJRA help reduce sedimentation from sand mines?
    • What happened to the Harris County investigation of Colony Ridge impacts?

    So many questions! Tonight’s your chance to ask them. And get answers from people who can do something about your concerns.

    Be there. Let local leaders know what your infrastructure priorities are.

    Posted by Bob Rehak on on 4/25/24

    2431 Days since Hurricane Harvey