In a new study published this week scientists at the Australian National University (ANU) have compared the benefits of improving farm dam water quality on cattle weight gain against the cost of renovation.
The cost benefit analysis found a 70 percent likelihood of substantial net economic benefit from renovating dams in poor condition to improve water quality.
The average per-farm Benefit-Cost Ratios identified by the study were 1.5 for New South Wales and 3.0 for Victoria, in areas where rainfall exceeds 600mm annually.
“Our analyses suggested that cattle on farms in NSW and Victoria would need to experience additional weight gain from switching to clean water of at least 6.5 percent and 1.8 percent per annum respectively, to break even in present value terms,” the study authors wrote.
“Monte Carlo simulation (a mathematical technique used to estimate the possible outcomes of an uncertain event – more info here) based on conservative assumptions indicated that the probability of per-farm benefits exceeding costs was greater than 70 percent.”
The analysis supports the case for focusing incentive schemes to improve livestock production in agricultural landscapes around renovating farm dams.
The study authors noted that while access to water is a critical aspect of livestock production, the relationship between livestock weight gain and water quality remains poorly understood.
According to the analysis, improving farm dam water quality could equate to yields of around $85m for the farms in NSW, and $519m for Victoria in prices derived from 2019.
The authors also note that renovating dams could improve sustainability by preserving biodiversity and reducing carbon emissions.
Some of the ways to improve the dams could include permanent fencing, adding dense grass areas, making sure trees were in areas that didn’t interrupt spill ways, and providing shallow areas for wildlife to live in.
Management interventions aimed at improving water quality in farm dams in south-eastern Australia. Credit: Dobes et al. 2021.
The study was conducted as part of a $5.93 million Federal Government funding program to measure the benefits of farm dams.
When the project was announced in 2019 Professor David Lindenmayer AO from the ANU Fenner School of Environment and Society said simple improvements to the design and management of farm dams, such as fencing and installing watering points could enhance production, drought resilience, animal welfare and biodiversity.
“These small improvements lead to deeper dams with cleaner water and which function better. And studies show with cleaner water, animals increase their weight by around a quarter.
“Good dams also provide a place where farmers can recharge the mind while going about their daily work.
“For many of the farmers we have spoken to, this is one of the biggest pay offs.
“Anecdotally we know the economic and other gains are massive. For the first time, this project will help us understand just how big they are.”
The project forms part of the ANU Sustainable Farms Initiative.
Key facts about benefits from best practice farm dams from ANU:
- Restricting stock access to a small section of a farm dam allows ground layer vegetation surrounding the dam to recover.
- Vegetation filters runoff from adjacent paddocks, which often contains large amounts of faecal matter, agricultural chemicals, and sediment.
- Filtering of inflow to the dam decreases turbidity, lowers bacteria loads, protects against algal blooms and decreases the risk of stock contracting water-borne parasites.
- Stock with access to clean water drink more and thus have greater rates of nutrient and mineral absorption.
- Trees planted around the dam shade the water, which reduce surface temperatures and evaporation rates, leading to cooler, more palatable drinking water and greater water security.
- Reliable access to water leads to positive animal welfare outcomes, which are closely tied to productivity.
- Farm dams can be micro-hotspots for biodiversity.
- Wetlands were once common in the sheep-wheat belt, but have largely been drained to make way for farmland.
- Currently, tens of thousands of farm dams dot the landscape and, if adequately restored, could help to compensate for the loss of natural water retention and purification systems.
To view the full paper click here