The Kingwood Service Association pier at the River Grove Park Boat Launch has reached the end of its service life and is being replaced.
The pier, which had grown old, sustained damage during recent floods. The planks had so much give in them, that I often wondered if they would hold me.
It’s Finally Time
After Harvey, though, KSA had so much work to do in the park – removing sand, replacing pavement, fixing fields, restoring restrooms, and dredging in front of the boardwalk – that replacement of the pier just had to wait, according to Dee Price, KSA president.
Earlier this year, KSA had a professional engineer draw up specs and then it solicited bids. “The winning bid was affordable and the contractor is doing excellent work,” said Price.
I would second that from everything I saw today at the park. Both the wood and workmanship appear top notch. This will make an excellent addition to the park.
Pics of New Pier Under Construction
Driving new piles to extend the pier. The four poles stabilize the boat while the pile driver in the center does its work.From this angle, you can more easily see how the pile driver slides forward and backward on rails to ensure alignment of supports.From ground level, you can see how substantial the wood is.
Expected Completion Soon
Price says she expects the work to be done this week or next, depending on weather. The launch remains open in the meantime, but is blocked periodically for short periods by the pile driver as you see here.
Posted by Bob Rehak on 11/2/2021
1526 Days after Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/11/20211101-DJI_0655.jpg?fit=1200%2C799&ssl=17991200adminadmin2021-11-01 21:44:062021-11-01 21:44:10KSA Replacing River Grove Boat-Launch Pier
The Diversion Ditch project would help address several potential problems. Expanding it would remove 62 structures from inundation areas and another 586 structures would benefit from improved local drainage. In addition, the project:
Can divert floodwater from Ben’s Branch, which will be a much more complicated project, taking more time.
Has a 300-foot right-of-way, of which only half is being used
Has bridges that already span the entire 300 feet.
Will help carry floodwaters from rapidly growing south Montgomery County.
History of Diversion Ditch
In the early days of Kingwood, Friendswood Development Company built the Diversion Ditch to reduce water flowing into Ben’s Branch. But since then, upstream development and larger rains have stressed the capacity of both Ben’s Branch AND the Diversion Ditch. Engineers estimate that peak flows have doubled since 1985.
Most of Ben’s Branch is Natural Channel
Ben’s Branch cuts diagonally through the heart of Kingwood. See red lines below. More than half its length – between Woodland Hills and Rocky Woods Drive is natural channel. Widening it will be complicated and take much time.
Red Line indicates approximate path of Ben’s Branch through Kingwood.
Ben’s Branch Now at 2-Year Level of Service
However, areas on both sides of Ben’s Branch are threatened by flooding as you can see in the image below from FEMA’s Flood Hazard Viewer.
Ben’s Branch once had a 100-year level of service, meaning it had enough carrying capacity to prevent homes from flooding in everything but a 100-year rain. Models based on new Atlas-14 rainfall probability frequencies indicate that the channel’s capacity is now down to a 2-year level of service. That means it will flood in minor rains, exactly as St. Martha School did last year.
Worse yet, Ben’s Branch has decreased to a 2-year level of service throughout its length.
HCFCD Kingwood Area Drainage Analysis
Source: Fema’s Flood Hazard Layer Viewer. Cross-hatched equals floodway, aqua = 100 year floodplain, brown = 500-year floodplain.Floodplains shown above are based on pre-Atlas-14 rainfall probability statistics. An Atlas-14 hundred-year rain is about 30-40% higher than the old hundred-year rain.
When flood maps are updated based on Atlas-14 statistics, those floodplains will likely expand…unless we do something to handle more floodwater before then.
However, Ben’s Branch will not move to preliminary engineering right away.
How to Protect Against Bigger Rains and More Upstream Development
The Kingwood Area Drainage Analysis sought to understand what we need to do to restore a 100-year level of service to all ditches and streams based on Atlas 14. Of the 19 ditches and streams studied, nine need improvement. The level of service for some, including Ben’s Branch, has been reduced to 2 years.
Expanding the Diversion Ditch is the fastest way to take pressure off of Ben’s Branch.
The Diversion Ditch intersects Ben’s Branch at the new St. Martha Church. It then flows south to Deer Ridge Park and then winds through River Grove Park. See the white line below.
Kingwood Diversion ditch (white line) intersects Ben’s Branch near the new St. Martha Church.
Expansion Capacity Already Built into Diversion Ditch
Engineers foresaw the day when Kingwood would need more drainage capacity due to upstream development in Montgomery County. They built the Kingwood Diversion Ditch to handle the extra stormwater. They also made the bridges over the diversion ditch wider than they needed at the time. Finally, they dedicated a flood easement on both sides of the ditch that was wider than they needed, so they could expand the ditch later without encroaching on neighboring properties. Here’s how it looks from the air.
Looking north across Northpark Drive toward Bens Branch, which cuts diagonally from left to right through the middle of the frame. Note the ample clearance under the bridge and the wide shoulders of the ditch. St. Martha Church is in the upper left.
Looking south toward Kingwood Drive at the Diversion Ditch. King’s Mill is on right in foreground.
Both Kings Mill and Kings Manor now drain into the Diversion Ditch. But they came long AFTER Diversion Ditch construction. Other new upstream developments that drain into the Diversion Ditch and Ben’s Branch include Brooklyn Trails and Woodridge Forest, both in Montgomery County.
As a result, the Diversion Ditch itself has decreased to a 2- to a 25-year level of service in places. However, it still offers a 100-year level of service in others.
Looking NE toward Deer Ridge Park from over Hamblen Road. A corner of Deer Ridge Estates is on the left. The diversion ditch cuts in front of the park (upper left to lower right) and goes into an area largely undeveloped on its way to the river (out of frame to the right).
Impact on River Grove Park
Once the Diversion Ditch passes through the area shown in the photo above, it enters wetlands and winds through River Grove Park. Two questions arise. How do we protect, from additional flow:
The park?
People downstream on the West Fork?
The first question is simple: split the flow in two. Take part through the undeveloped area west of the park. See the green below.
Green Line represents one possible route for diversion of the diversion ditch.
The second question is more complicated. We need a retention basin to hold the extra stormwater until the peak of any flood passes on the West Fork. But where? The closer you get to the river, the lower the elevation. Because of that, the basin could fill with floodwater from the river before it fills with floodwater from upstream. Fortunately, some large tracts of land exist on higher ground that could be purchased. HCFCD estimates the need at 1248 acre-feet. Preliminary engineering should start soon to address these issues.
Upstream Development Not Addressed by Analysis
Unfortunately the Kingwood Area Drainage Analysis did not address upstream development issues in Montgomery County. That was beyond the scope of work. Regardless, such issues must be addressed somehow, someday soon. Otherwise, even the improvements we invest in today could soon be overwhelmed by additional floodwaters.
In that sense, these channel improvements represent a stopgap measure. The real solution lies in making everyone in the region realize that we are all in this together.
The ten remaining channels/streams already offer a 100-year level of service. Therefore, no improvements are needed. HCFCD felt Taylor Gully should be the next priority after the Diversion Ditch. But the possible purchase of Woodridge Village may require re-thinking project requirements. Specifically, if Woodridge turns into a giant detention basin, the channel may not need as much deepening or widening.
Posted by Bob Rehak on 10/20/2020
1148 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/10/RJR_4304.jpg?fit=1500%2C1000&ssl=110001500adminadmin2020-10-20 21:09:102020-10-21 09:32:19HCFCD Recommends Expanding Diversion Ditch as First Priority in Kingwood
The storm deposited so much sand in this park, there were times when I doubted it could be restored. The park’s comeback is a remarkable tribute to a handful of dedicated volunteers and contractors (led by Dee Price and Bruce Casto), with big assists from the people of Kingwood, the Army Corps of Engineers and Kayden Industries.
Here are the slides and text from Price’s presentation to the BizCom meeting. The presentation also includes information about KSA, which newcomers may find helpful.
Dee Price BizCom Presentation on River Grove Park
Good Morning. I’m going to spend a few minutes talking about the recovery of Kingwood’s River Grove Park from the impact of Hurricane Harvey. But first let me give you a brief overview of the Kingwood Service Association aka KSA.
KSA is a Texas non-profit corporation that was chartered in September 1976 by the Kingwood developer. Its stated purpose is to provide for community, civic, and social welfare in the Kingwood area and to promote the health, safety, and welfare of the Kingwood area residents.
Carrying out this purpose has evolved over the years as Kingwood became part of the City of Houston.
Representing 32 community and commercial associations throughout Kingwood, KSA has continued to be a focal point in working community-wide issues that impact multiple villages in Kingwood.
KSA owns, operates, and maintains the five major parks in Kingwood. It also maintains the two major entries into Kingwood at Kingwood Drive and North Park Drive. KSA actually owns the entrance area on Kingwood Drive on which the ponds are located.
Like many areas in Kingwood, River Grove Park was heavily impacted by Hurricane Harvey. A huge amount of sand was deposited in the park. In addition, many of the park facilities suffered a significant amount of damage. The pictures on the slide above illustrate the amount of damage suffered.
It took a significant amount of effort to recover from the damage caused by the hurricane. First, we had to remove 364 truckloads of sand. We had to drill a new well, pressure wash all of the park facilities, and repair the damage to the facilities. We also had to restore the sports fields closest to the river that had been inundated by sand deposits.
The final step of dredging the portion of the river along the park’s perimeter had to be put on hold until the US Army Corps of Engineers completed their project to dredge the San Jacinto River. The Corps removed the big sand bar formed during Harvey that was blocking access to the river from River Grove Park. This was a big help to KSA and very much appreciated.
Once the Corps was finished with their dredging project, KSA was able to proceed on its project to dredge the area along its boardwalk and boat ramp. The picture shows that a large amount of sand was deposited in the area by Harvey.
Since the dredging had been put on hold for 3 years, vegetation took hold on the sand and had to be removed before the dredging itself could begin.
Once the vegetation was removed the removal of the sand could proceed. Ultimately, the project removed 10,000 cubic yards of sand, dewatered the sand on-site using a dewatering machine, and then hauled off the sand to an approved location.
The project took 3 months to complete including working during the early stages of the Covid-19 pandemic. The boat ramp, which was closed in 2017 after Hurricane Harvey, was re-opened in April 2020 and has been heavily used since that time.
The last slide is a picture of the park after the first stage of recovery had been completed and the park was re-opened in March 2018. That concludes my discussion. Thank you very much.
The spirit and tenacity of volunteers in Kingwood are one of the things that make this such a great place to live.
Posted by Bob Rehak on 8/7/2020with thanks to Dee Price, KSA, the KSA Parks Committee, Bruce Casto, Kayden Industries, the Army Corps of Engineersand people of Kingwood
1074 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/08/LHCC-Bizcom-08-06-2020_Dee-Price_Page_09.jpg?fit=1023%2C765&ssl=17651023adminadmin2020-08-07 09:41:422020-08-07 09:41:57The Remarkable Restoration of River Grove Park After Harvey
I always associated the word “Riviera” with a coastal region in France and Italy on the Mediterranean. But being a student of language, I frequently look up words that I think I know. Much to my surprise, I learned that the word has a second meaning. It also applies to any coastal region with a subtropical climate and vegetation. The origin of the word stems from 18th century Italian. It literally meant “seashore.”
History and Meanings of Riviera
The 20-volume Oxford English Dictionary (OED), which is really a history book of the language, indicates that railroad barons frequently used the word in the 1900s to lure vacationers to coastal areas around the world. OED’s last entry is from the October 19, 1943 edition of the Saturday Review, an influential magazine at the time. The OED quoted the Saturday Review as saying, “Every properly equipped nation must have a Riviera.”
Getting From There to Here
The term occurred to me when I saw the scene below while flying up the San Jacinto West Fork last Sunday near River Grove Park. So it is with tongue in cheek and humor in my heart that I apply the term to River Grove.
Looking NW. Partying on the sand dune outside Kingwood’s River Grove Park on a lazy Sunday afternoon.
Looking northeast at the same sand bar two weeks after Harvey.At this point, the River Grove parking lot was still covered with 4-5 feet of sand.
No Burger Barns or Tatoo Parlors, But…
Now the sand bar seems to be a popular stopping off point for people running the river and trying to squeeze a little more sunshine out of the day.
It may not be the French/Italian Riviera. Nor is it the Redneck Riviera. You won’t find people here for spring breaks, water parks, tattoo parlors, beer joints, crab shacks, burger barns or t-shirts.
But the sunshine is warm, the water cool, and it doesn’t require a trans-Atlantic flight or a 14-hour drive.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/06/20200530-DJI_0128-2.jpg?fit=1200%2C900&ssl=19001200adminadmin2020-06-06 19:22:032020-06-06 19:41:43River Grove Riviera: Park Adds New Feature
The River Grove Park boat launch has finally reopened. Hurricane Harvey sanded it in two and half years ago.
These were among the first boaters at River Grove after the opening.Further downstream, the river was crowded with personal watercraft.Jet skis near Romerica property downstream from River Grove.South of Kingwood Country Club, I spotted four more boats.
Remember, River Grove is restricted to people with KSA stickers. River Grove is a private, not a public park. It’s restricted to Kingwood residents whose villages belong to KSA.
Hope you enjoy the great outdoors. The reopening of the boat launch has been a long time coming.
Just remember to be careful. There’s plenty of room for you and your boat out there on Lake Houston to practice social distancing…as you see in these photos.
Also remember that barges and dredges are still moving up and down the river. They can’t maneuver like you. So keep your distance.
Barges offloading spoils from mouth bar directly across river from River Grove Park.
Safety first, last and always.
Posted by Bob Rehak on 4/22/2020
967 Days after Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/04/20200421-RJR_1090.jpg?fit=1200%2C800&ssl=18001200adminadmin2020-04-22 21:06:302020-04-22 21:06:58River Grove Boat Launch Reopens
Ever since Harvey filled up the lagoon next to the River Grove boardwalk, Kingwood residents have clamored to restore the area. This week they got their wish. Kayden Industries has removed its two dredges and the giant “shaker” that separated sand from water. This morning, all that remained of the operation was a front-end loader, a giant pile of sand, and dump trucks rapidly carrying it away. They should be done with the operation this week.
Damage Due to Harvey
Here’s the story in pictures starting with Harvey.
The lagoon next to the popular boardwalk at Kingwood’s River Grove Park has totally filled in with sand deposited by Hurricane Harvey.Harvey also left a 10-foot high sandbar that blocked the drainage ditch that runs through River Grove.
Remove up to five feet of sand covering the parking lot and areas near the boardwalk
Restore soccer fields also covered in sand
Repave access roads and parking lots undermined by churning floodwaters
Inspect the boardwalk to ensure it was structurally sound.
Draw up a dredging plan for the lagoon with an engineer.
Identify a suitable place to put the spoils.
Bid the job.
Approve the plan and expenditure.
Note height of sand in River Grove parking lot relative to parking sign in background.
It was a monumental effort. Dee Price, KSA President and steward of River Grove Park, and Bruce Casto, KSA’s maintenance man, deserve kudos for spearheading the effort and saving this park.
Between Harvey and the end of 2019, vegetation had grown up over the sand deposited in the lagoon.
Step one in the dredging: Remove the vegetation that had grown on the sand.
Then, Kayden Industries mobilized a mini dredge. The dredging took seven weeks.
Drying the Spoils Before Trucking
Kayden also brought in this giant machine to separate sand from water. It works like an oilfield shaker used to separate drilling cuttings from drilling mud.
Last Week, Demobilization Began
Almost two months after it started, Kayden began demobilizing. Resident Josh Alberson captured the image below with his drone.
Last week, Kayden Industries started demobilizing their equipment. Here we see one of the two dredges getting ready for removal from the water. Kayden brought in a smaller dredge when the City lowered the level of the lake suddenly. The first dredge is up on blocks behind the pile of sand.Photo courtesy of Josh Alberson.This morning, where the shaker once stood, nothing but some sand remains.A giant pile of sand still blocks the boat dock.But dump trucks were lining up to receive the sand and carry it to a placement area in Humble out of the flood plain.The finished job: a beautifully restored lagoon, complete with some marshes to attract birds.
Water along the boardwalk is 3-5 feet deep, so don’t let kids play in it. That could be dangerous.
Some Repaving Left to Do
All the heavy traffic has taken a toll on park roads. “Everyone needs to understand that the paving problems on the road between the gate and the first stop sign were there long before we started trucking dirt,” said Dee Price, KSA President. “We have patched that area numerous times in the past.” Price said KSA needs to mill and re-pave that piece of road as the group did with the soccer road. Price plans to put that project in the next fiscal-year budget. But for now, she says, “We need to patch it again until we can do the major improvement next year.”
Posted by Bob Rehak with thanks to Josh Alberson for the drone imagery
958 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/04/20200413-RJR_0511.jpg?fit=1200%2C800&ssl=18001200adminadmin2020-04-13 13:20:592020-04-13 13:21:44River Grove Dredging Done, Only Cleanup Left
Since Hurricane Harvey, KSA has worked diligently to restore the damage to River Grove Park. It has been a massive job. Harvey filled in the lagoon in front of the boardwalk; left five feet of sand in the parking lot, disc golf course, and playing fields; and deposited a sand bar more than a quarter mile long and 12 feet high in front of the boat dock.
River Grove Waterfront on 9/14/2017, two weeks after Harvey. Lagoon filled in, five feet of sand filled the parking lot, and a 1400-foot, 12-foot-high sandbar blocked off the drainage ditch that empties the western third of Kingwood.
Army Corps Restored River Access
The Army Corps cut a channel through the sand bar that blocked the drainage ditch that empties the western third of Kingwood. That was a huge sigh of relief for a large part of Kingwood. But much work remained to restore the park itself. Among the last items on the agenda: restoring the lagoon and boat ramp access.
It’s hard to capture the scope of dredging operations from the ground – especially with access restricted for safety reasons. But last week, I did a flyover and captured these pics from a helicopter.
Looking west toward the River Grove Boat Ramp and Lagoon. Photo taken March 5, 2020. The dredge started by the boat dock and is working upstream now in the lagoon. Note the dewatering plant in the parking lot and the growing pile of spoils waiting for removal on the right.
In the photo above, you can see the 50-foot strip where Kayden removed vegetation. That will be the limit of dredging. KSA plans to remove 4-5 feet of sand from this area. The area still covered with grasses will remain wetlands. It will provide cover, habitat and food for birds and other species. That should help make River Grove a destination for birders again.
Harvey deposited sand several feet deep on the peninsula that defines the River Grove lagoon. That unfortunately killed many of the trees there. The wetlands remaining in the lagoon are now more important than ever. Eagles nest in the trees in the upper right of this photo on Romerica property.The dredge started in the area in front of the boat dock and is working its way upstream in the lagoon. Water from the dredge goes through a floating pipe to a dewatering plant in the parking lot. Water is then returned to the lake in a closed-loop process.
A Bit of the Oil Field Comes to River Grove
The dewatering plant separates sand and sediment from the water before returning the water to the river.This is the same type of equipment used in oilfields to separate drilling cuttings from drilling mud, before recycling the mud.
Expected Finish By End of March
KSA expects the dredging project to finish by the end of March, weather permitting. However, the boat ramp may not open immediately. The heavy equipment has damaged the asphalt in the parking lot. Repairs and restriping may take a few weeks more.
Originally, KSA expected to remove 10,000 cubic yards of sediment. The contractor now predicts they will remove 11,000 to12,000 cubic yards to complete the scope of work.
Other Park Improvements
The good news: When all of this is done, River Grove Park should be back and better than ever. During repairs, KSA decided to:
Convert several of the soccer fields from “league fields” to “public fields.” Residents have long requested that change.
Change the speed bumps to milder speed humps in the traffic circle. Boaters have long requested that.
Posted by Bob Rehak on 3/9/2020
923 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/03/20200306-RJR_9605.jpg?fit=1200%2C800&ssl=18001200adminadmin2020-03-09 15:54:072020-03-09 15:57:09New Aerial Photos of River Grove Park Show Extent of Dredging Project
River Grove dredging has finally begun. Silt and sand deposited by Hurricane Harvey 2.5 years ago is being removed from two areas: the boat launch and boardwalk. KSA obtained a final permit from the City of Houston and equipment arrived yesterday.
Boardwalk First Priority
As you can see from these pictures, the contractor wasted no time. Equipment has already started removing silt from in front of the boardwalk.
Mechanical dredging equipment excavates area near boardwalk.
Additional equipment is being staged from the parking lot.
Contractors closed off the parking lot adjacent to the boat launch for public safety.
Contractors have already started removing the top layer of vegetation adjacent to the boardwalkthat sprouted since Harvey.
Pictures From Immediately After Harvey
A huge sandbar deposited by Hurricane Harvey blocked the Kingwood Diversion Ditch which drains the western third of Kingwood.Note sand covering the parking lot. It was 5 feet deep in places.Taken 9/14/2017.
The lagoon in front of the boardwalk was badly silted in.Taken 9/14/2017.
Pictures Taken February 2020 Before Start of Dredging
Photo taken 2/13/2020 shows how vegetation grew up on silt in lagoon.Aerial photo of boat launch area taken on 1/20/2020 shows that Army Corps opened up the drainage channel to the river. However, the area near the boat launch remains too shallow for most boats to launch safely.
Dredging and cleanup should take about 6 weeks. Completion will make eager boaters and park visitors very happy. River Grove has long been one of the most popular parks in Kingwood.
Posted by Bob Rehak on 2/18/2020
903 Days after Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/02/IMG_0480-rotated.jpg?fit=1512%2C2016&ssl=120161512adminadmin2020-02-18 13:05:072020-02-18 13:06:01River Grove Dredging Begins
Yesterday’s second post about the wettest AND driest decade in our lifetimes helped explain something I’ve been puzzling about. Multiple mouth bars are forming around Lake Houston. The loss of tens of thousands of trees during the drought exposed soil. One massive storm after another then washed that soil toward the lake. Voila! Mouth bars.
Diversion Ditch Blockage
We already cleared the massive side bar that blocked the mouth of Kingwood’s diversion ditch.
The ditch (center left) that empties the entire western part of Kingwood at River Grove Park on the west fork of the San Jacinto was virtually closed off by this sandbar that formed during Harvey. An estimated 500+ homes above this point flooded.
West Fork Blockage
The Army Corps removed about a fifth of the West Fork mouth bar.
Army Corps at work removing a small portion of the West Fork Mouth Bar.Photo courtesy of BCAeronautics.
This is not surprising for a man-made lake that’s 65 years old. Dams have a tendency to hold back sediment. Sediment drops out of suspension where the moving waters in a ditch or stream slow down as they meet the still waters of a lake.
These mouth bars increase flood risk for everyone who lives near them. They form sediment damns that restrict the conveyance of the channels behind them. That forces water up and out of the channel into people’s living rooms.
Clearing the Way for Political Solutions
So how do we get rid of these mouth bars?
State Representative Dan Huberty is organizing another dredging program that should start soon. Primary targets will be the West and perhaps East Fork Mouth mouth bars. These smaller bars represent, believe it or not, a larger problem though. They fall into a jurisdictional quagmire. Does the water body they are on belong to adjacent property owners, the City, the County, or the State?
That will determine where the money for dredging comes from. And more importantly, whether the money that is already available can be used to attack the problem when a dredge is in the lake.
The bar is in an unincorporated section of Harris County. But the City owns the shoreline, and usually the first few hundred feet of channels.
Who will take ownership of problems like Walden’s? These details still need to be worked out.
HB1824 May Help
Ironically, HB1824, which I criticized because I believe it opens the door to river sand mining, may help in cases like Walden’s. The bill allows Harris County Flood Control to take sediment from the San Jacinto and its tributaries without obtaining a permit or paying a fee as long as HCFCD deposits the sediment on private land. (Remember: Lake Houston IS the San Jacinto River.)
I suspect the Walden ditch will become precedent for how such minor tributaries are treated. Walden’s nearness to the West Fork mouth bar would argue for making it part of any dredging program there.
A new year, new challenges!
Posted by Bob Rehak on 1/1/2020with photo and video from Jack and Greg Toole, and BCAeronautics.
855 Days since Hurricane Harvey and 104 since Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/01/DJI_0032.jpg?fit=1200%2C675&ssl=16751200adminadmin2020-01-01 19:54:352020-01-01 20:20:31Multiple Mouth Bars Forming Around Lake Houston; Check out Walden’s
After a year of dredging, the Army Corps and its contractors are gone. Even though they didn’t get all of the West Fork Mouth Bar, they made dramatic conveyance improvements on the West Fork as these before/after photos show.
Sand Island Before Dredging
The first was a blockage that dredging contractors nicknamed “Sand Island.” It sat in the middle of the river just downstream from River Grove Park in Kingwood. According to the Corps, it blocked 90% of the river.
Sand Island formed during Hurricane Harvey. Boats that drew 18 inches of water could not navigate upstream past this giant sandbar.Photo taken 9/14/2019.
Sand Island After Dredging
Sand Island is now Gone Island.Photo taken 12/3/2019.
The Corps removed approximately 15 feet of sand over a 15 acre area that was 566.7 feet wide at its widest point. An acre is about the size of a football field. So this would be like stacking sand on a football field 225 feet high (15×15)! And that doesn’t even include the sand they removed from the channels on either side of the island in the background.
Sand Island Dredging Profile.
Diversion Ditch Bar Before Dredging
A second huge sand bar deposited by Harvey blocked the Kingwood Diversion Ditch, also at River Grove Park. The Diversion Ditch empties the western third of Kingwood. Approximately 600 homes flooded above this one blockage. They were in Barrington, Kingwood Cove, Trailwood, Kingwood Lakes and Kings Forest.
Diversion Ditch (center left) was virtually closed off by a new sandbar deposited by Harvey.Photo taken 9/14/2017.
Army Corps measurements show that at its highest point this bar measured 10 feet about the water surface. It forced water coming out of the ditch to make a 90 degree left turn where it then hit another downstream blockage.
Diversion Ditch Bar After Dredging
Photo taken 10/2/2019 after dredging opened up the channel and reduced the downstream bar.Photo of same area taken on 11/4/2019, but looking upstream.
The Corps dredged a channel 150 feet wide through this bar to a depth of 35 feet above sea level. That’s about 7.5 feet below the normal water surface elevation of the Lake. The channel narrowed to 50 feet wide where it meets the mouth of the ditch.
From the highest point on the bar to the target depth, the Corps removed 17.5 vertical feet of sand. From the mouth of the channel to the outer edge of the bar measured 750 feet.
Comparison in Satellite Images from Google Earth
Here’s how this section of the river looked from a satellite BEFORE dredging. The numbers refer to the discussions above.
Here’s how it looked AFTER. (Note this image was taken on 2/23/19 and the dredge was still removing sand island.
Altogether, the Corps removed approximately 2.3 million cubic yards of sediment. Even if the Corps didn’t finish the mouth bar, that’s a lot to be grateful for. Thank you, FEMA, Army Corps, Great Lakes Dredge and Dock and Callan Marine.
Have a merry Christmas!
Posted by Bob Rehak on 12/24/2019
847 Days after Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2019/12/BeforeAfter.jpg?fit=1200%2C1600&ssl=116001200adminadmin2019-12-24 11:44:182019-12-24 12:10:24San Jacinto West Fork Before-After Photos Show Dramatic Conveyance Improvements from Dredging
