Source: Is Zimbabwe drilling itself dry? | Sunday Mail (Local News)

Leroy Dzenga
Senior Reporter

GLOBAL water demand is expected to grow by 55 percent by the year 2050.

It would be unsurprising to find Zimbabwe on the list, as early signs of resource stress are already showing.

The SADC region’s population is growing faster than the pace with which water infrastructure is expanding, a situation which has forced households and communities to take matters into their own hands.

Groundwater is already under strain, and it appears like the country has begun a gradual but ominous slide. Experts are calling on authorities to provide quick, evidence-based responses to the situation.

Mr Craig Tinashe Tanyanyiwa, a PhD Candidate in Civil Engineering (Water Sensitive Design and Urban Stormwater Harvesting) at the University of Cape Town explained the circumstances facing Zimbabwe.

Groundwater is kept in aquifers, which are sponges or vessels which hold water. Aggressive abstraction of water, though ruinous, has different outcomes based on the geography of the place. There can be confined, semi confined and unconfined aquifers. This categorisation has important implications. “Confined aquifers are found in areas which are rocky, with the water found under layers of rocks. The water does not infiltrate easily (or at all) into the ground. This can be good as it can reduce groundwater contamination from leaky sewer lines,” said Mr Tanyanyiwa.

However, unconfined aquifers are usually found in areas where the geography is dominated by sandy soils. Although they do not require deep drilling, they pose a comparative health danger.

“For unconfined aquifers, the water is within the sand pores and is abstracted by drilling into the water table. These wells can often be shallower than the ones found in confined areas. Unconfined aquifers are more susceptible to contamination as infiltration occurs more easily,” explained Mr Tanyanyiwa.

Although usual concerns on the incessant and unregulated drilling of boreholes are usually long term, some of the consequences are already being felt. “Our groundwater use can potentially lower the water table to the point where we start seeing land subsidence,” said Mr Tanyanyiwa.

Land subsidence is when land-due to the drastic altering of the supporting underground system, through factors like depletion of underground water-causes the ground to collapse.

This causes natural disasters like flooding and earth fissures.

As an example, Timbulsloko, a village in Indonesia, was a decade ago a normal farming and fishing community in which people could drive on roads enjoying serene coastal views.

However, over time, due to land subsidence and the resultant floods which have become a fixture in their community, people now canoe around the village. They have made peace with the new reality of living while submerged in water, and some parts of the country may in the future bear the same brunt.

“However, the more immediate concern is groundwater contamination. If one well gets contaminated then the risk of wide contamination emerges. Moreover, our sewer systems are terrible which means contamination is probably inevitable at this stage,” said Mr Tanyanyiwa.

In 2018, Zimbabwe recorded 10 421 cholera cases and 69 deaths, after residents in Glen View at Tichagarika Shopping Centre drew water from a contaminated borehole which seeped from a nearby leaking sewer pipe.

The incident, whose consequences became a public health nightmare for authorities, put into perspective the extent to which groundwater depletion can threaten lives.

As it stands, borehole water in Harare is not considered 100 percent safe as a result of the spirited abstraction. In 2017, then Health Minister David Parirenyatwa made a startling revelation when he said 95 percent of boreholes from low-density areas in the capital were contaminated.

Government in 2019, through the District Development Fund introduced borehole chlorinators, as a way of trying to purify contaminated underground water — a sign of the complications the excessive drilling is presenting. The country’s borehole population continues to grow, with some drilling being done beyond the authorities` radar. University of Zimbabwe scholars, Emelder Tagutanazvo and John Bowora, in their 2019 study on Institutions and the Sustainability of Community Borehole Water Supplies noted that in ward 13, 14 and 15 of Sengwe communal lands in Chiredzi District, there are 58 boreholes. A conservative average extrapolated from the figures could translate to 15 boreholes per ward.

Using those figures, multiplied by the 1958 wards in the country, the country’s borehole population could be more than 29 000. The Zimbabwe National Water Authority (ZINWA) said they are keeping an eye on the sustainability of activities around borehole drilling.

“Domestic use of groundwater is not limited but caps can be put on the extraction of groundwater for commercial purposes. For example, through Statutory Instrument 90 of 2013, the abstraction of bulk water from boreholes is controlled. ZINWA as the water authority and the Environmental Management Agency also constantly monitor wetlands because wetlands are very critical in the recharge and replenishing of ground water,” ZINWA marketing and corporate communications manager Mrs Marjorie Manyonga, told The Sunday Mail. Sub-catchment councils, which manage the growth of boreholes, have noted the emergence of a borehole drilling black market.

Representatives of the Nyagui sub-catchment told The Sunday Mail that there has been a proliferation of phantom drilling companies wreaking havoc in their jurisdiction.

The Nyagui sub-catchment measures around 4 900 square kilometres, covering parts of Marondera, Goromonzi, Murehwa, Shamva, Bindura, and a section of Harare.

Other water lobbyists are calling on authorities to ensure that the law is upheld to avert a crisis. Community Water Alliance national coordinator Mr Hardlife Mudzingwa said:

“Firstly, drilling of boreholes — if not carefully managed — can deplete ground water resources and there is already a tendency by residents to drill their own boreholes at household level within high-density suburbs. This is against provisions of the law where drilling of boreholes within 300 square metre residential stands is prohibited.

“The reasoning behind this law is two-fold; protecting ground water resources from depletion emanating from numerous boreholes and maintaining health standards through prevention of damage to sewer and water,” said Mr Mudzingwa.

He called for quality control on the boreholes.