Water Resources (# 88)


Managed Aquifer Recharge Can Maximise Groundwater Storage

Managed aquifer recharge (MAR) can be a successful means of providing replenishment to depleted groundwater systems. Supplementing the recharge that naturally occurs can help offset groundwater use while maintaining ecologically dependent levels.

With the need for sustainable, long-term water resource management in much of the world, MAR is increasingly being viewed as suitable to balancing environmental benefits and economic needs.

In New Zealand, regional water planning efforts on South Island are looking at MAR and the various methods that can be applied as part of an effort to find solutions.

These before and after images of the Hinds River show the use of a normally dry river channel as a natural managed aquifer recharge mechanism to replenish groundwater supplies.

These before and after images of the Hinds River show the use of a normally dry river channel as a natural managed aquifer recharge mechanism to replenish groundwater supplies.

Overuse of groundwater in this area has resulted in declining springs, rivers, and groundwater levels. This has limited the full storage potential of the underlying aquifers.

Golder's MAR assessment process is designed to help identify the use of natural geologic features for potential groundwater storage. For this particular project east of the Southern Alps on the Canterbury plains, a MAR recharge trial infiltrated surface water through an existing gravel river bed. The Hinds River watershed area consists of sloping plains, underlain by gravel-rich sediment, which contain groundwater fed from rainfall and from seepage from the rivers and irrigation systems that cross them.

An existing spillway structure was used to divert the recharge water from one of the major rivers that flows from the Alps, allowing the water to be recharged to the target aquifer via natural infiltration.

Golder led the development of this project, and monitored and reported on the flow of the diverted water and the levels of groundwater in wells around and downstream of the discharge point. A pre-trial risk analysis and post-trial assessment of the results were done. We took into consideration water quality and quantity, and at the same time have maintained a strong community involvement focus.

As an ongoing project, we will seek to continue dialogue with the Ngāi Tahu peoples of the Maori culture who live in the area, and establish collaborative partnerships with the regional government and the local community who are very interested in how and where MAR might be best suited.

RELATED RESOURCES

Article: Bower, R.J., Williams, H.W., 2011. “Managing Groundwater Storage – Aquifer Recharge in New Zealand’s Water Future”. Water by Water New Zealand (WaterNZ). Issue 170 p. 57-59, July (not online).

Article: Bower, R.J. Henry, R., 2011. Infiltration Gallery Testing for Integration into Dual-Purpose Irrigation Systems – Managed Aquifer Recharge in Walla Walla River Basin, Oregon. Proceedings: Managed Aquifer Recharge Symposium (Operations and Clogging) National Water Research Institute (NWRI), Irvine, California, USA. January.

Article: Bower, R.J., 2010. Stabilising and Restoring an Aquifer and Springs – Managed Aquifer Recharge in the Walla Walla River Basin, Oregon (2004-2010). Proceedings: 2010 New Zealand Hydrological Society Annual Conference. Dunedin, New Zealand. December.

Article: Bower, R.J., Lindsey, K.J. 2010. Shallow Aquifer Recharge as a Water Management Tool: Six Years of Operations for the HBDIC Recharge Site (2004-9). Official Report to Oregon Watershed Enhancement Board, Oregon Water Resources Department, Washington Department of Ecology, and Bonneville Power Administration. WWBWC – Milton-Freewater, Oregon. April.

Article: Bower, R.J., Petrides, A. 2009. Accounting for Groundwater in Watershed Management. Southwest Hydrology Magazine. Vol. 8, Number 2. Pages 24 – 26.