From Retention Pond to Underground Stormwater Management System

A property owner in the Denver metro area partnered with their contractor, 303 Landscapes, to resolve their retention pond problem.  303 Landscapes with the support of CPS Distributors and NDS Drainage installed an underground stormwater management system.

The problem area: retention pond (and mud pit) in the backyard.

In order to move forward, the team needed to know exactly what they were up against. They partnered with an engineer to help better understand the site, the soil, and the requirements needed to successfully hold the amount of water needed. With the new information, NDS Drainage was brought on to review the plan and recommend the products needed to exceed project expectations.

In order for the system to store the water capacity at a 100-year storm magnitude, it needed to hold 44,285 gallons of water. In order to make this happen, 303 Landscapes needed to install 2 – 24″ inlets, 50 of NDS StormChambers (1 row of 6 chambers, 5 rows of 7 chambers and 1 row of 9 chambers), 3 sediment traps, and 1 weir structure, all on a 10” gravel base.

NDS StormChamber systems are highly effective for stormwater detention and retention. In addition to detaining stormwater, they also recharge the groundwater, maintain base flow, and improve water quality with the formation of a biomat, which acts as a natural filter, on the surrounding stone and soil.

Each unit is flexible, strong, and easy to install, saving the contractor time and money. Made from high-density weight polyethylene HMWPE, NDS StormChambers offer a 100-year life expectancy and can withstand extreme environments.

How NDS StormChambers work:

The open bottom chamber has perforations along the sidewalls for water to enter. The chambers collect the excess water while the open bottom allows the water to percolate through the gravel base and into the ground. Each chamber has a storage volume of 561 gallons. This does not include storage volume from surrounding rock. The rock around the system has a 40% void space.

If the system should ever reach it’s maximum storage capacity, the excess water would begin to fill the overflow exiting out of the weir structure and directed to a nearby pond roughly 100 yards away.

(See it in action:

Ideal for under athletic fields, golf courses, parking lots and other areas that effected by excess flooding and slow drainage, NDS StormChamber systems offer a low cost, low impact development solution for retention, detention, conveyance & water reuse.

Do you need help with a stormwater management system? Contact your local CPS representative for assistance.