Northpark Detention Basins

Excavation of Northpark Detention Basins Starts

Excavation of the decorative ponds that will double as Northpark detention basins at US59 began this week.

Contractors will stockpile the dirt in two places for now: behind Duncan Donuts and at a sand mine on Sorters-McClellan Road several blocks to the west. Contractors will use the dirt later to level the road surface and build access ramps for the bridge over the Union-Pacific Railroad tracks.

In other Northpark-expansion news this week, Entergy still has not started moving its utility poles and transformer.

However, CenterPoint has almost finished relocating its gas line under the road’s center drainage ditch to the south side of the road. CenterPoint also surveyed the north side of the street to place a second line there.

Finally, the Lake Houston Redevelopment Authority (LHRA) is close to finalizing a drainage agreement with the Union-Pacific Railroad. For more details, see below.

Beginning of Entry Pond Excavation

Contractors will excavate the entry ponds/detention basins in several stages. For now, they will excavate down to the water table. Later, they will excavate below the water table, pumping water into new storm sewers as they dig.

Then they will place a liner at the bottom of each pond.

Finally, the ponds will be filled to the level of the storm sewers with a combination of well- and rainwater. But that will come much later.

The distance between the top of water in the ponds and the surface of the ground will retain stormwater to help prevent flooding of the intersection during heavy rains.

The photos below were all taken on 1/13/2024.

Looking at beginning of excavation of north pond. US59 and feeder on left, Northpark on right.
Looking west toward US59 bridge. These contractors appear to be defining the margins of the pond. Note stakes.
Excavated dirt on right waiting for shipment to a stockpile. Note storm drain on left and the wet earth that indicates proximity to water table.

Bens Branch, which crosses under 59 farther north, often overflows and backs up toward the Northpark intersection. The pipe above will carry water into the pond instead, thus reducing flood risk.

Start of one stockpile behind Duncan Donuts and Public Storage.

Where the Dirt Will Go

The stockpiled dirt will eventually be used to level the roadway over box culverts (when installation is complete) and also to build up ramps for the bridge over the railroad tracks.

When contractors finish placing box culverts, the stockpiled dirt will help level the center of the roadway, which will contain two additional lanes of traffic – one going each direction.

The bed must be raised to the level of the manhole shown above.
Looking west toward 59. Power lines belong to Entergy. They must be moved back to approximately where the fire hydrant is now. Yellow/green flags indicate route of new CenterPoint gas line.

Moving the utility poles back will create room for turn lanes next to the bridge over the rail tracks. The turn lanes must be at ground level for traffic turning north or south onto Loop 494.

Project managers first asked Entergy to move its power lines 2020. The utility still has taken no action. Ditto for the transformer below located near the Exxon station at 59.

Entergy transformer in red circle must also be moved back to make way for additional turn lanes.

An Entergy consultant claimed the company needed 50 weeks to move the transformer above.

The City is reportedly considering legal action against Entergy because of construction delays.

Meanwhile, Entergy continues to promote its social responsibility, even as it holds up construction of the only all-weather evacuation route for 78,000 people.

Railroad Agreement Should Be Resolved by End of January

In the good-news department, the last remaining issue with UP will hopefully be resolved within a couple weeks, according to project manager Ralph De Leon. The Lake Houston Redevelopment Authority sought permission to tunnel stormwater under the UP tracks to Ditch One. The railroad company required no more than a quarter-inch displacement of the tracks. Engineers figured out way to do it by splitting the flow from one pipe through two smaller pipes.

The Agreement covers both the aerial easement over UP’s tracks for the bridge and the railroad’s acceptance of the Construction Plans. The stormwater drainage pipes under the tracks held up UP’s final approval of the plans. Now that that has been resolved, UPRR is ready to accept the plans.  

Approval by the City will occur in the form of an Ordinance adopted by City Council.

The City of Houston contributed $15.4 million to the Northpark Project. Here is the contract between the City and Lake Houston Redevelopment Authority.

For More Information

De Leon said, “Once the UP agreement is signed, and CenterPoint and Entergy relocate their utilities, we can start building roads. Residents should then see a significant increase in in construction activity.”

For more information about the project including construction plans, visit the project pages of the LHRA/Tirz 10 website. Or see these posts on ReduceFlooding:

Posted by Bob Rehak on 1/13/24

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