Making your own garden water slide might be easier than you think. In the long run, it's cheaper than a commercial version. You can also customise the length and width of your slide when you make it yourself. With some simple tools, you can have a garden water park in no time, and playing games with your slide makes for maximum use.
Get a smooth tarpaulin sheet or plastic cover. Fold it in halves or quarters, keeping it as long as possible. Make sure that there are enough layers to provide some cushioning against the ground.
Get two lengths of garden hose the same length as the tarpaulin or plastic cover, and add a few metres to reach the tap. Using the screwdriver, punch holes along one side every few centimetres. This is where the water will squirt out, so make sure to put enough holes to keep the plastic surface completely wet during use.
Using the screwdriver, punch holes every 15 cm (6 inches) along the edges of the tarpaulin. Using the plastic zip ties, affix the tarp to the hoses, with one hose on each edge. Leave a few feet of hose at the front of the tarp to reach the tap.
Attach the two-way hose splitter to your water tap. Attach one hose to each end of the splitter.
Lay the water slide out on a soft surface, such as a lawn. There should be enough room for the entire slide to stretch out, plus several feet of space at the end for safely getting off the slide.
Give everyone a water gun. As one person goes down the slide, squirt him with the water guns. The faster someone slides, the harder it is to hit him. Or, on a particularly hot day, try to slow your speed and get even more soaked.
Use a stopwatch to time everyone as they go down the slide. See who can go the fastest or the slowest down the slide. It's actually harder to go slower, so that can be even more competitive.
Find out who can slide in the most creative way. You could try sliding sitting up, backwards, or any other way you could think up. Just be careful when getting on and off the slide.
Add an inflatable pool at the end of the slide (you may have to prop up the slide with more plastic sheeting to keep from running into the side of the pool). Find out who can make the most spectacular splash or landing into the pool.
Use an inflatable kick board to raft down the slide. This lets you slide faster and can help if your slide is thin or if the ground is especially hard.
Race rubber ducks down the slide. Mark each duck with a number or name, and send them on down the slide. The fastest duck is the winner.
If you have a second tap, or a four-way hose splitter that allows for enough water pressure, you can put two slides side-by-side. Then, two people can race at the same time.
Don't jump from a great height or distance onto the slide, since there is not a lot of cushioning against the ground. Wear safety gear when using the screwdriver to avoid injury.