SP13 - Rivers

Purpose

To establish guidelines for the safe design of moving water in channels and designated rivers.

Definition

Rivers are level channels of moving water created by pumping water at predetermined flow rates. The unidirectional channels are between 1.5m and 3.0m wide, with water from 0.75m to 1.2m deep and a length determined by available space usually between 20m and 50m indoors. 'Lazy rivers' may be defined as ‘water moving less than 1.5m per second’ and 'rapid rivers' as ‘water moving greater than 1.5m per second’.

Description

Gradual depth changes at both river exit and entry should be at a gradient of 1:14 and should be slip resistive. Steps should not be used.

Walls and Floor

The river should be finished with smooth walls and floors to reduce the risk of cuts, bruising and abrasions to bathers as they brush against or are forced against them.

The height from static water level to the pool edge should be such that the water is retained within the river channel.

A bather should also be able to grasp the edge should the need arise.

Consideration should be given to bather safety and their ability to support themselves above water level when in difficulty. Should the height and finish (flat tiles) of the pool edge be such that some bathers may have difficulty in reaching or grasping it, consideration should be given to the provision of a flexible rope system along one wall of the river. The rope fixing system should be recessed into the pool wall. The rope system is preferable over the alternate solid stainless steel or similar hand rail due to the risk of bather impact and entrapment.

Water Flow

The water should only flow in one direction.

The water flow should not create an undertow, eddy currents or cross currents. Should variable speed flow rates be available and used resulting in the river being either lazy or rapid (as defined above), appropriate bather notification should be used to indicate prevailing water conditions. This may include signage or audible notification.

An emergency stop button should be located within close proximity for use by facility supervisors and lifeguards in emergency situations.

Circular style rivers with outlets and inlets in close proximity require special consideration as they may create a vortex. This effect may continue with bather movement alone even when booster pumps are switched off. Some bathers may be unable to escape the flow.

Water flow created by wave motion will also require special consideration including:

1. Waves entering both river inlet and outlets thereby creating a higher wave within the river at the meeting points
2. Possible higher pool edges to reduce the chance of flooding of pool concourse or planters
3. The effect on wave motion caused by depth of water and width of river

Note: Designers should give consideration to the use of models to ascertain possible water movements during the pool design phase.

Entry and Exit

No obstruction such as hand rails or entry / exit ladders or steps should enter into or protrude into a river.

Suitable free deck space adjacent to the river should be provided for lifeguard supervision and access.

Bridges and Overhangs

In cases where objects such as rocks or bridges overhang the surface of the River, it is recommended that sufficient clear space for the intended use of the river is provided above the static water level. Users should be able to easily pass under the overhanging object without risk of impact to their head while standing on the pool floor.

This height should be increased where wave action enters the river.

All bridges and overhangs used a walkway should comply with the Pool Concourse Guidelines.

References

• Building Code of Australia - 2006. Australian Building Code Board.
• AS 2416 - 1995; Design and application of water safety signs.
• AS 1428.1 - 2001; Design for access and mobility Part 1: General requirements for access - New building work.
• AS/NZS 2416:2010 Water safety signs and beach safety flags Part 1, Part 2 and Part 3

Previous Versions

• FD10 River Design, Issue 2 1 November 2007