HydroCon Pipe
HydroCon pipes are specified to improve the performance of bioretention systems. By delivering pre-treated stormwater to the subsurface of a bioretention or stormwater filter system, common concerns over surface crusting and clogging of filtration media can be avoided, thus considerably extending service life.
Other application of HydroCon pipes include; water quality improvement, detention, drainage, street ponding, infiltration, aquifer recharge, and stormwater harvesting.
HydroCon permeable concrete pipes are made of a no-fines concrete mix with basalt aggregate. They are fully porous across the entire pipe circumference.
Standard HydroCon pipes have diameters of 300mm and 500mm with flat base.
A range of non standard sizes and shapes is available on request.
Please contact HydroCon for detailed information about exfiltration rates, load testing, treatment efficiencies.
Flat Base
(Standard)
Flat base permeable concrete pipes.
Heavy Duty Flat Base
(Non-standard)
Heavy duty flat base permeable concret pipes.
Round
(Non-standard)
Round permeable concrete pipes.
Surface Drain Cover
(Non-standard)
Surface drains with permeable concrete base and non-permeable concrete cover.
While HydroCon offers as much assistance as possible with the design of stormwater systems, it does not provide a design service. However, detailed guidelines on designing HydroCon pipe systems have been developed.
HydroCon Pipe Systems – Music Modelling Guidelines provide guidance to designers wishing to incorporate HydroCon permeable concrete pipes in their designs. The document aims to show designers how MUSIC (Model for Urban Stormwater Improvement Conceptualisation) software can be used to:
- configure a water quality treatment system incorporating HydroCon pipes;
- calculate the number of pipes required.
The document provides two examples of the use of HydroCon pipes in bioretention systems:
- where surface storage is available; and
- where surface storage is limited or unavailable.
Blacktown City Council WSUD Standard Drawings
HydroCon pipe systems have been incorporated into Blacktown City Council’s water sensitive design (WSUD) approach to their water management. Council has developed a WSUD toolkit, which includes Standard Drawings. The drawings provide general design guidance on key details and list complying solutions acceptable to Council.
HydroCon permeable concrete pipes are intended for the management and treatment of stormwater ‘at source’.
A HydroCon pipe system requires an inlet pit to which a number of pipes are connected. HydroCon pipelines are terminated with a standard stormwater pit or an ‘end-plated’ pipe. A terminating configuration ensures that flow velocities within a HydroCon pipeline are very low. HydroCon pipes should not be connected directly to outflow pipes.
An overflow mechanism is required to allow water to surcharge when flows exceed HydroCon pipeline storage capacities. Input pits provide this function. Where surcharge from more than one pit is desirable or where pipelines are longer than 40 m, stormwater pits may be used to terminate HydroCon pipelines. Using more pits will help to distribute stormwater more evenly across the surface of the bioretention or media filtration system.
HydroCon pipes are very easy and quick to install. A step by step guide to installation is shown below and can be downloaded.
HydroCon pipes are easily and swiftly installed by adopting the following procedures:
- After excavation of a trench or basin, inlet pit(s) are constructed. The pits may be formed up on site or placed in position as precast units. The trench or basin should then be filled with specified filtration media (eg sand, gravel or granular activated carbon) compacting in layers. Continue to fill until the level of the media is 50 mm above the bottom of the outlet hole of the inlet pit.
- Pipes can be transferred to the site with lifting tynes or manoeuvred into position with harness or other equipment.
- Position pipes, working out from the inlet pit and successively checking level and alignment of each pipe. Pipes are laid at zero gradient. Where an end-plated pipe is to be used to terminate the pipeline, make sure that the correct end of the initial pipe is inserted into the inlet pit. 10-12 cm wide geotextile strips should be cut to such a length that will wrap around the joint between pipes with a 15-20 cm overlap. Geotextile strips placed externally around the joint of each pipe prevent media entering the joint, particularly during installation.
- Use a stiff mortar mix to seal the connection between the initial HydroCon pipe and the inlet pit. This operation may be undertaken at any time prior to back filling of the trench.
- When pits and pipes have been placed in position, the trench/basin is backfilled with media to the depth specified in the system design. Ensure that the media is carefully tucked in and lightly compacted around the HydroCon pipes and in doing so that positioning of the pipes is not disturbed.
The exfiltration performance of HydroCon pipes can be maintained by conventional industrial cleaning methods. Cleaning restores permeability of the pipes to near new condition.
HydroCon pipe systems have a distinct advantage over other WSUD stormwater treatment systems in that stormwater pollutants are captured within the pipes and removed in situ without the need to replace the entire system. The frequency of cleaning can be reduced by installing upstream, and regularly maintaining, an appropriate gross pollutant trap (GPT) to minimise accumulation of sediment and debris within the HydroCon pipes and associated inlet pit or pits.
Internal surface of the pipes should be inspected regularly for build up of sediment on the base and walls of the pipes. The extent of any build up should be apparent from examination of first couple of pipes from each inlet pit, as well as the pit itself. Excessive accumulation of material on the walls of the pipes will reduce the rate of exfiltration.
Case Studies
