Northpark Update: Lane Switch, Paving, Tunneling, Enclave

6/5/25 – The Northpark Drive Expansion Project has been a beehive of activity recently.

A major traffic switch will happen Friday.
Crews have paved several blocks of new westbound lanes and are working their way toward the railroad tracks.
They have finished the first pit for boring under the UnionPacific tracks and are getting ready to place the boring machine into it. They have also started excavating the receiving pit on the west side of the tracks.
Contractors at the Northpark Enclave continue to work even as Montgomery County Precinct 4 is trying to set up a meeting between Montgomery County Engineering, City of Houston, EHRA (the Enclave’s engineering company), and HNTB (the Lake Houston Redevelopment Authority’s engineering company). The purpose: to discuss concerns about potential overflow from the development’s retention pond during extreme weather events into the evacuation route for 78,000 people.

Lane Switch

Westbound traffic between Loop 494 and US59 will be routed to recently paved lanes on the north side of Northpark starting Friday, June 6.

According to Ralph De Leon, Northpark Expansion project manager, “Beginning June 6th at 9pm, Harper Brothers Construction will shift westbound Northpark Drive traffic to the newly constructed westbound lanes.”

The contractor will then install new storm sewer pipes and construct new concrete roadway between the eastbound and westbound lanes. This shift should last approximately 6 months. And no additional lane changes will take place during that time in that area.

De Leon provided this map to help motorists understand Friday’s change.

That same area looks like this from a lower angle.

*Crews will reroute traffic to the lanes on the right with the orange traffic cones.*

Westbound traffic now in the middle will move to the right and crews will begin work in the middle.

Paving

During the last few months, work on the north side of Northpark east of the railroad tracks has focused mainly on utility relocations and drainage installation. Now, crews are starting to pave that area working from east to west – toward the tracks.

Note the fresh concrete on the left below.

*Reverse angle. Looking W from same location. Crews are working on pavement prep work, i.e., rebar placement.*

Boring Under Union Pacific Tracks

*Steel pipe previously stockpiled south (left) of Northpark has been moved to the north side in preparation for the bore.*

*Workers have completed the steel frame for the boring operation and poured a concrete floor for the bore pit.*

They have also placed a section of railroad tracks into the pit. The boring machine will later be placed on the tracks.

*On the far side of the tracks, you can see them starting to excavate the receiving pit.*

Two steel pipes will run under the tracks side by side to convey storm water toward the Diversion Ditch from the area on the west side of Loop 494. As crews push each section in, they will weld a new section on.

Enclave Construction

Contrary to earlier reports, construction at the Enclave has not stopped during a peer review of the subdivision’s drainage.

Northpark Enclave — *Photo taken 6/4/25 at approximately 2 PM* *showed activity throughout the site.*

Victoria Bryant, Montgomery County Precinct 4 Project Coordinator says that she is trying to set up a meeting between the engineering companies, MoCo Engineering and the City of Houston.

Pictures below show activity on the site.

Northpark Enclave drainage and detention basin — *Culvert installation almost reached the development’s detention basin* *at 2PM on 6/4/25.*

Northpark Enclave drainage construction — *More drainage being installed on 6/3/25*

Drainage Concerns

Meanwhile, construction plans show that the detention basin could overflow into the only evacuation route for 78,000 people during extreme rainfall events.

Northpark Enclave construction plan detail — *Enlarged and cropped detail from construction plans.*

But it doesn’t take a 100-year rainfall to create a 100-year flood in the Kingwood Diversion Ditch.

The photo below taken by Kingwood flood activist Chris Bloch during the May 2024 flood shows runoff in the Kingwood Diversion Ditch reaching above the bottom of the Northpark Drive Bridge, which was above the predicted 100-year flood level.

But the closest Harris County Flood Control rain gage showed that the May 2024 event that caused water to reach that high was approximately a 5-year rainfall by today’s Atlas-14 standard.

Northpark Bridge during High water event — *Photo courtesy of Chris Bloch*

But there’s more. Plans for the bridge show that the bottom is at 75.76 feet.

About a half mile downstream, drainage from the Enclave and the rest of Kings Mill crosses under Russell Palmer Road and enters into the Diversion Ditch.

Water in the Diversion Ditch at the bridge was higher than the crown of Russell Palmer Road at the detention basin.

When water in a receiving ditch is higher than water in a connected detention basin, it creates back-pressure on the water in the basin. Water can actually flow into the basin from the ditch.

At a minimum, higher water in the Diversion Ditch would slow the water coming out of Kings Mill and the Enclave. That raises the height of stormwater in the detention basin(s) and keeps it there longer.

Also, note that the outfall pipe for the Kings Mills Detention Basins is at the BOTTOM of the Diversion Ditch. (See below.) That exacerbates the back-pressure issue.

Kings Mill outfall into Kingwood diversion ditch. — *Route of stormwater from Kings Mill Detention Basin (right) to Kingwood Diversion Ditch (left)*

Conclusion: Mismatch Between Regulations and Reality

The Diversion Ditch has become seriously overburdened with runoff from subdivisions that were developed when the rainfall probability estimates used by Montgomery County were 40% lower than they are for this area today.

That may or may not cause the Enclave detention basin to overflow into Northpark during a REAL 100-year event. It will be interesting to see what the engineers determine. Only they can tell how high, how far, and how long the water will back up.

Chances are small that the Enclave detention basin will overflow into Northpark during an evacuation. But the stakes are huge.

Posted by Bob Rehak on 6/4/25

2836 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.