Ponds Tanks & Dams
A concrete pond is possibly the best and longest lasting type of water storage facility but can be permanently ruined through poor construction and is also potentially the most expensive to build. A concrete pond should be poured in one continuous process to ensure all seams and joins bond before setting. They are much like a swimming pool. First ensure drainage pipes and framework are in place then after the pour use a concrete vibrator to settle the mix and remove air pockets. Cure, clean with acetic acid and fill and drain the pond to remove lime over a period of weeks.
Concrete livestock troughs could be a good small alternative and at around 5000 litres are relatively portable and multipurpose. These are precast so simply purchase and have delivered.
Lined ponds can be created starting with earthmoving and followed by laying a liner, of which there are many options. The earth should be free of sharp objects, flattened out with a layer of sand and a trench need to be dug around the outside of the dam as an anchor point. Seams are "welded" using an adhesive. Anchor by laying the liner over the outer trench and fill with sandbags.. Any pond or dam being made may need approval and and safety should be at the forefront of the owners mind - consider fences and also a slow decline at the ponds edges. Ensure animals can't tread on the edges leading to potential damage. According to Nick Romanowski, zooligist and author, 1 in 3 lined ponds leak. This will lead to regular maintenance. Lined ponds are also somewhat difficult to drain.
An earth lined pond is an option by which clay soils are used to resist the water. Bentonite is now often used as a layer to seal the pond which is a clay product. Clays can dirty the water so a layer of loamy soil can be used over the top of the clay. Bentonite can be applied in a few different ways, it can be rotary hoed into the top layer of the soil, it can also be applied as a blanket over the soil after it has been flattened and rolled, or finally, while the dam contains water it can be sprinkled over the water surface though this method is somewhat less reliable.
Fibreglass tanks are another option where if a prefab design is used it can be cost effective. Smaller tanks are easier to manufacture and are more economical. They are created using a resin which is mixed with a hardener and glass fibres that are sprayed into a mould. Fibreglass can become brittle over time when exposed to the elements but such a tank is relatively light weight compared to concrete and thus has the bonus of being mobile.
Choosing a Site
When you are selecting a site for a freshwater enterprise initially there are two main considerations. Flat ground is a high priority, largely due to earthmoving costs if dams are being constructed. If this is the case then heavy clay soils are necessary. Also, understanding what the land was used for prior to the venture is important. What fertilisers / chemicals were used previously?
There are other considerations. What infrastructure does the site already offer? Are there sheds and other useful buildings? Is there a bore and what is the quality of the water? Are there any sites available that already have dams, ponds or tanks that can be converted easily for use?
The climate is important. How balanced is the weather system? How much artificial input would be required to support the production system? Does the climate match both animals and suitable plants? How does water runoff occur and what is the potential for harmful chemicals to pollute this water? What lies upstream and what possibility is there that excess agricultural chemicals and nutrients will cause an issue?
Location also impacts access to consumables, materials and manufacturing. Is the site close to concrete / fibreglass manufacturers or to feed suppliers as excessive transport could incur extra costs. Likewise, you have to consider the transport costs for exporting the produce. It's also necessary to think of what access you will have to laboratories or experts in the field and what other agricultural enterprises are in the area that your business could link with to value add to your product.
Finally consider what government policies are in place. Are there state bans on certain species? Are there grants/support in that state.