Developing managed aquifer recharge (MAR) to augment irrigation water resources in the sand and gravel (Crag) aquifer of coastal Suffolk, UK

K M Hiscock; N Balashova; R J Cooper; P Bradford; J Patrick; M Hullis

doi:10.1016/j.jenvman.2023.119639

Developing managed aquifer recharge (MAR) to augment irrigation water resources in the sand and gravel (Crag) aquifer of coastal Suffolk, UK

J Environ Manage. 2024 Feb:351:119639. doi: 10.1016/j.jenvman.2023.119639. Epub 2023 Dec 5.

Authors

K M Hiscock¹, N Balashova², R J Cooper², P Bradford³, J Patrick³, M Hullis⁴

Affiliations

¹ School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK. Electronic address: k.hiscock@uea.ac.uk.
² School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
³ Felixstowe Hydrocycle Ltd, Unit 3b, Tuddenham Road Business Centre, Tuddenham Road, Grange Farm, Ipswich, IP4 3QN, UK.
⁴ Growth, Highways and Infrastructure, Suffolk County Council, Endeavour House, Russell Road, Ipswich, IP1 2BX, UK.

PMID: 38056326
DOI: 10.1016/j.jenvman.2023.119639

Abstract

Managed aquifer recharge (MAR) offers a potential innovative solution for addressing groundwater resource issues, enabling excess surface water to be stored underground for later abstraction. Given its favourable hydrogeological properties, the Pliocene sand and gravel (Crag) aquifer in Suffolk, UK, was selected for a demonstration MAR scheme, with the goal of supplying additional summer irrigation water. The recharge source was a 4.6 km drainage channel that discharges to the River Deben estuary. Trialling the scheme in June 2022, 12,262 m³ of source water were recharged to the aquifer over 12 days via a lagoon and an array of 565 m of buried slotted pipes. Groundwater levels were raised by 0.3 m at the centre of the recharge mound with an approximate radius of 250 m, with no detrimental impact on local water features observed. The source water quality remained stable during the trial with a mean chloride concentration (133 mg L^-1) below the regulatory requirement (165 mg L^-1). The fraction of recharge water mixing with the groundwater ranged from 69% close to the centre and 5% at the boundary of the recharge mound, leading to a reduction in nitrate-N concentration of 23.6 mg L^-1 at the centre of the mound. During July-September 2022, 12,301 m³ of recharge water were abstracted from two, 18 m boreholes to supplement surface irrigation reservoirs during drought conditions. However, the hydraulic conductivity of the Crag aquifer (∼10 m day^-1) restricted the yield and thereby reduced the economic viability of the scheme. Construction costs for the MAR system were comparatively low but the high costs of data collection and securing regulatory permits brought the overall capital costs to within 18% of an equivalent surface storage reservoir, demonstrating that market-based mechanisms and more streamlined regulatory processes are required to incentivise similar MAR schemes.

Keywords: Conjunctive water resources management; Crag aquifer; Groundwater; Irrigation water resources; Managed aquifer recharge.

MeSH terms

Groundwater*
Sand
United Kingdom
Water Resources*
Water Supply

Substances

Sand