Salinity doesn’t just affect nature and agriculture, it impacts cities where saline water is corroding surfaces and killing gardens.
There’s a vast amount of salt in Australia that originates from the erosion of rock minerals and sea salt carried in the wind and rain. Native vegetation has evolved to tolerate salt, with deep roots and a high thirst for water, and while nature was untouched the salt stayed put. But when modern farming arrived, deep root plants were cleared and shorter root crops using less water were planted. This caused unused rainfall to start leaking down to the water table, pushing the water and the salt up. Enter salinity. This process continues today causing excess water and salt that destroys soil, ecosystems and costs millions of dollars in loss of agricultural quality. In Australia scientists are looking at ways to restore agricultural systems to capture water and nutrients just like the natural environment does.
Like salinity in nature, urban salinity has appeared in cities as development has replaced natural vegetation and excess water seeps up into the ground. This excess causes the water table to rise creating saline waterlogged soil. Excess moisture and saline seepage can spread into infrastructure and foundation, climb into walls, corrode pipes and equipment and contribute the loss of biodiversity. Left untreated, it can lead to expensive structural, plumbing and landscaping repairs.
We’ve listed five tips to reduce the impact of urban salinity at home, and what to consider if you have a swimming pool.
Spot and reduce salt damage and corrosion at home. Watch out for these signs:
- When damp saline soil comes into contact with a porous material like concrete or bricks, the salt can spread through the matrix and force it apart. When water evaporates, salts crystallise. They can cause blisters and cracks in paint and cause external surfaces to strip and erode.
Rusted or corroded metal elements and fixtures
- Metals can quickly corrode from saline soil and saline water. Corroded pipes can leak which can expedite corrosion further.
Discoloured or wilting plants or grasses
- The effect of salt varies on plants but saline water can be toxic and cause defoliation, stunted growth or death. Foliage that dies from the outside in (causing a halo effect) could indicate stress from shallow water tables.
Solutions to reduce salinity
- Fix leaks from cracked swimming pools, broken gutters, poorly connected downpipes, leaking taps and cracked underground pipes that can cause wet soil.
- Check if your drainage is effectively diverting water. Most hardware stores can suggest solutions.
- Keep your garden as far away from your house as you can.
- Plant native species and control the amount you water them. Ask a garden centre for tips and suggestions.
- Research salt damp solutions or call out a professional to assess the damage.
- Consider switching to a freshwater pool to reduce corrosion to metals and damage to plants and rock features from salt and chlorine splash out.
Salinity and Pools
Salt corrodes – just ask anyone who’s experienced the effects of salinity. Salts, chlorines and other added pool chemicals in a salt chlorination system can cause corrosion of pool finishes, rust metal elements and strip gardens to expedite the effects of salt damage.
Salt water chlorination adds salt (mostly sodium chloride) to pool water and converts it to chlorine using electrolysis when water passes through a treatment cell. While it’s a commonly used pool sanitisation system in Australia, it requires continual chemical backup like stabilisers and algaecides that are restricted in some parts of the world. If a salt water pool isn’t correctly treated, it can blow out the chlorine levels which can cause further damage, in addition to a raft of health risks.
To reduce the impacts and risks of salinity, minimise the salt and chemical additives in your pool. Enviroswim is a fresh water swimming pool system that completely removes added chemicals and stabilisers that promote rust and corrosion.
Enviroswim’s electronic fresh water sanitisation system meets New Zealand drinking water standards, so it’s safe to water the garden and a much kinder option for pets and wildlife that drink out of pools, especially in hotter weather.
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