Dams to Wetlands: Part 3 - Time to Plant

November and December are the best months to plant in and around the water of the dam.

As the dam water receeds, the space becomes accessible and new plantings have a chance to become established before being inundated by the Autumn rains.

The objective of the plantings is to:

1. Stabilise the soil around the dam
2. Create habitat for native wilflife, particularly  frogs
3. Become water purifiers
4. Improve the aesthetics of the space

We took the chance to put in about 70 plants as close to the water as possible. These included the River Bottle Brush (Callistemon sieberi) as we as various rushes (Juncus) species sourced from the local nursery and being of local provenance.

All these plants have the benefits of being fast-growing, while the Juncus is particularly easy to plant, not requiring staking or covering. The local Macropods also don't seem too interested when there is tastier grass to be found elsewhere.

The area we chose to plant was the gentle slope down the hill, which is basically a mud flat, full of silt and nutrients. This is in contrast to the dam-wall side, which is rocky and would be more difficult for the plants to establish.

The plantings on the mud-flat area should quickly spread and start to fill that space.

Rushes planted in the silt

Several Rush species

See the new plants to the right and below the dam

We'll check back in a few months and see how these are progressing.

Rain Harvesting First Flush and Leaf Diverter Review

Six months ago, I installed a leaf diverter/filter as well as a first-flush system on our rain water tanks that we use for drinking and household water, to ensure we have a clean water supply.

Now that I've had some time to see them both in action, I thought I would share my findings.

What is a leaf diverter?

As the name suggests, this is a device that prevents leaf and other large debris from entering your rain water tank. The mesh filter also prevents insects, particularly mosquitoes, from entering the tank.

While most poly tanks have a filter, this is not always the case for older tanks such as our concrete tanks. In this case, I purchased the "Rain Harvesting" brand leaf diverter from Bunnings.

Here is the link to their product page.

What is a first flush diverter?

This device diverts a volume of water from entering your tank which is likely to contain roof contaminants such as soil/dust, bird droppings, fertiliser residue and other small particles or chemicals that accumulate on your roof between rain events.


Again, I used the one available from Bunnings.

The kit contains the floating ball and associated special T-join that has a moulded ball seat. Also included is the tube emd-cap, which allows for a steady release of diverted water, allowing the tube to empty once rain has ceased, resetting the system automatically.

The kit contains several rubber washers that have different sized pin-holes in them, allowing you to control the rate of water release and therefore the timing for the system to reset. Choice of hole size is based on the size of the diversion tube, which can be quite large. The recommendation is to have as large a tube as possible given your space limitations.

In this photo you can see the floating ball in the background as well as the assembled end cap.

Overall impressions

My experience of installing the first flush diverter was problematic to say the least. The instructions were very unclear. I needed to use several YouTube videos as well as study the individual parts to finally understand how to assemble the unit. This is definitely an area the company could improve in.

However, after finally working it all out, the final system is excellent and works very well. It is easy to clean and would be easy to replace if anything should fail.

I was surprised by how much debris accuulated in the bottom of the diverter pipe, thereby preventing this from entering our drinking water. It was smelly, black mud. On this basis alone I would now never have a tank without a first flush diverter.

The Leaf Beater does as it suggests and was easy to install. The amount of leaf debris that can accumulate on the mesh is quite high, but this does not prevent water from passing through it at a high flow rate during, for example, a thunderstorm.

Once it has stopped raining, it is a simple task to remove the mesh, which is sitting in the device and not clipped or screwed in, and empty it of its leaves and twigs.

Recommendation

I would recommend both these devices. I note that Rain Harvesting now have newer versions of the first flush diverters. My only hope is that they have improved their instructions.

The Leaf Beater is really for people that do not already have a tank mesh filter, but if you don't, then this product will do its job well.

How to Build a Double Bench with Table

I recently built this double bench with a centre table to replace some camp chairs and brighten up the place.

This is from a design that I made on the brilliant Sketchup program based on other designs I found there.

The primary improvement I made was to slope the seat 5 degrees, which leads to a more comfortable sitting position and does not overly complicate the build process if you have a mitre saw.

The Sketchup design can be found here.

The Sketchup model looks like this:

Materials

For all the sides, rails and supports, I used 90 x 45 mm recycled timber.

The front horizontal rail is bigger at 140 x  45 mm. This height is not critical - adjust your build accordingly.

The seat slats are 108 x 19mm floorboards cut down to 86 mm wide. You could use any decking timber.

The table and arm rests were milled from an old piece of timber to 130 x 28 mm. This was custom-milled. As long as they are all the same thickness, the overall piece will look good.

I used 14 - 10g x 75 mm stainless steel screws for the majority of joins.

8 - 10 g 40 mm screws were used to attach the seat slats.

The piece was finished with outdoor decking oil.

Step 1: The Frame

To build the frame you need to cut the correct angles of the rails: 5 degrees for one end and 10 degrees for the other. This leads to an overall slope for the back of 15%.

The first cut to make is the small bevel where the front seat slat will sit. This cut needs to be first so that you can align the timber correctly on the mitre saw. This is a 5 degree cut of only 3mm.

Once you have made this cut, do the other 5 degree cut for the front, then do the 10 degree cut for the back.

Once complete you can assemble the frame:

Step 2:  The Sides

Making the sides is straight-forward. Cut all the pieces, including the 15 degree cut to the back of the top rail and join all the pieces.

In this design I chose to cut a notch in the vertical front pieces to support the front horizontal rail. To do this a did multiple passes on the mitre saw with the depth set to 45 mm (half the depth of the vertical piece). This adds a nice effect to the overall piece. If this is too hard for you, or if you don't have the right tools, just leave this step out and cut your front rail the same width as the rear rail.

To get the pieces square, measure and triangulate and adjust accordingly. If these pieces aren't square, then the rest of the build will be difficult.

Attach these pieces to your frame.

Step 3: Seat Slats

The seat slats need to go on next as you will have to temporarily remove the upper side rail to gain access to drilling and screwing.

I cut a bunch of 9mm spacers to help lay out the slats.

Once you have finished attaching them, reattach your side rails.

 

Step 4: The Back

The back pieces need to be square and all the same length. It is also nice to round them over to take away the bulky feel of the overall piece.

To round them, I drew a semicicle using a round saucer. Try to aim for a radius of about 45 mm (half the width of the timber). Then I cut using a jigsaw. On the recycled hardwood I used, this was quite difficult as the timber burns as the saw turns. Sanding tidies this up.

Once you have your four pieces, attach them to your frame:

The side pieces can be used to stabilise the two at each end, while the middle pieces can do with an extra screw. I used 3 screws in for the middle pieces. All others have 2 at each point (4 in total).

Step 5: The back slats and table supports

The back slats go next to ensure that the back rails are the correct distance apart. If you attach the top slat first, you can correct for any warping in the vertical rails.

Once you have all the slats on, go ahead and attached the pieces that will support the centre table, taking care to align the rear piece carefully to ensure the table will be level. It's best to do this on a level surface and use a spirit level to align the rear piece.

Step 6:  The Table and Arm Rests

Finally, attach your table and arm rests.

I decided to shape the arm rests with a jigsaw to give a nicer overall look, but this is optional. You may alternatively round the rear corners the same as the back supports to soften the look without overcomplicating the build.

I hope you enjoy this design. If you build your own or have any comments or suggestions, please let me know.