Terre Arch

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Terre Arch™ Precast Concrete Multi-Arched Infiltration Structure

Terre Arch™ is a precast concrete multi-arched structure used for infiltration of stormwater runoff.

Terre Arch™ does not require any foundation or footer. Installation is directly upon a stone subbase.

Terre Arch™ is HS-20 load rated with stone backfill to top of arch, solving site design issues when depth to water level and depth of cover present problems for HDPE pipe or arches.

Terre Arch™ design allows for confined space entry throughout the entire installation.

Model Size Storage
Terre Arch 26 34”x8’x19’ 338.89ft3 2.23ft3/ft2
Terre Arch 48 55”x8’x20’ 637.74ft3 3.98ft3/ft2

When the total cost to create a cubic foot of underground stormwater storage is considered; Terre Arch™ is a cost competitive precast concrete solution for an underground stormwater infiltration structure.

Terre Arch™ is a manufactured treatment device- best management practice (MTD-BMP) used for post-construction stormwater management.

Terre Hill Stormwater Systems recommends pretreatment of stormwater runoff prior to entry into any subsurface structure to maintain the long term useful life optimum functionality of the underground structure.

To learn more about Terre Arch™ and Terre Hill Stormwater Systems, please contact a member of our Stormwater Team

Gene Lamanna
Stormwater Sales

Serguei Diaz
Stormwater Project Coordinator


  • Terre Arch™ TA 26 -
  • Terre Arch™ TA 48 -
  • TA26 Distribution Manifold Standard -
  • TA48 Distribution Manifold Standard -

General Chart

NJ Chart


  • Specifications TA-26 -
  • Specifications TA-48 -

Plan Notes

  • Plan Notes Terre Arch™ 26 -
  • Plan Notes Terre Arch™ 48 -


  • Terre Arch™ Installation Instructions -



Case Studies

Frequently Asked Questions

How does the cost of a Terre Arch™ compare to the plastic, HDPE or CMP  products?

The important cost is the “Installed Cost of Void Space Underground”; precast concrete as a material cost, may cost more than plastic, HDPE or CMP; but, the installed cost is the critical issue.
Terre Hill’s “just in time” delivery reduces material handling allowing each Terre Arch™ to be installed every 5 minutes; HS-20 load rating allows direct access for all installation equipment; and reduced stone requirements results in reduced project time and reduced man hours, creating an installed cost per gallon or ft³ that is very cost competitive; in many cases less than the installed cost of plastic, HDPE or CMP products.

When the project requires “prevailing wage rates” on-site labor costs are significant; Terre Arch™ reduces labor costs to a minimum.

How does the structural strength of the Terre Arch™ compare to plastic and HDPE products?

Terre Arch™ 4” thick precast concrete arch structural strength and elasticity modulus far exceeds that of plastic or HDPE
Precast concrete has very low creep and relaxation compared to plastic or HDPE

No Subsidence or Collapse danger with precast concrete.

What are the dimensions/weight/capacities of the Terre Arch™ ?

Model Structure Arch Height Arch Span Storage Load Rating Weight
Terre Arch 26 34″x8’x20″ 26″h (internal) 52″w (internal) 338.62ft3
HS-25 13,500 lbs</td
Terre Arch 48 55″x8’x20″ 48″h (internal) 72″w (internal) 605.74ft3
HS-25 15,700 lbs</td

What is the minimum soil bearing capacity required for a Terre Arch™?

Minimum soil bearing of 3000 psf; as verified by the Engineer, with a 12” stone base, is required to support the Terre Arch™. If cover on the Terre Arch™ exceeds 3’, the stone base may need to be increased to balance the bearing  load with the bearing capacity.

What is the normal installation time for a Terre Arch™?

With a properly excavated and prepared base a Terre Arch™ can be set every 5 minutes; with installation of up to 30,000 ft³ in 1 day, including cover & backfill.

What is the design life of precast concrete?

100+ year usual life

What Warranty does Terre Hill Stormwater Systems provide?

4 Year Labor & Material Warranty