Wagga Wagga, the largest inland city in New South Wales, is situated on the banks of the Murrumbidgee River. It has a population of about 57000. Since salinity is a serious problem in the city and its surrounding areas, Dad took me there for a few days in July to see for ourselves the evidence of salinity. With the help of a booklet called "Wagga Wagga Urban Salinity Tour", published by the City Council, we had a very fruitful tour in the city. It took us to places of interest where we could see effects of salinity and how the Council was tackling the problems.

The City Centre of Wagga Wagga

Causes of Salinity in Wagga Wagga

Wagga Wagga is located in the Murrumbidgee Catchment. The growth of the city of Wagga Wagga has changed the catchment's water balance. As a result, the watertable has risen. Farming first tipped this balance through vegetation removal. Urbanisation then dramatically increased recharge from around 1mm to 50mm per year. Consequently, around 400,000 tonnes of salt flow past the city each year. That is, 1,096 tonnes per day! Salt reaches the river from creeks draining highly saline land and salty groundwater seeping into these tributaries and the river itself.

Murrumbidgee River at Wagga Wagga

Much of Wagga Wagga is situated in a large drainage basin with a small catchment discharge point, thus preventing water from leaving the basin readily. Groundwater levels increase behind this constriction and build up until they reach the surface causing waterlogging and salinity. Water is entering the system faster than it can leave, causing an imbalance in the system.

How Geology Affects Watertable

The natural shape of the land is a major reason for salinity in Wagga Wagga. The main catchment in Wagga is bounded by hills, and the only place the groundwater can drain out of the basin is a narrow gap through the lowest part along Glenfield Road near the Juvenile Justice Centre. The salty groundwater builds up behind this narrow gap causing the watertable here to be very close to the surface in this area.

Signs that salinity was attacking Wagga Wagga first appeared in its showground in 1994 and it was not long before a crisis developed. The main arena, which is the focal point of show activities, began to die off. Consequently, the City Council has to put a lot of resources into solving the problem and preventing it from worsening.

Evaporation Basin		Water Drained from the Showground