Mining copper amid glaciers in the Chilean Andes
While in transit on her way back from a trip to Chile with Anglo American, Pippa Howard shares her reflections on the importance of sustainable water management high in the Andes Mountains. Mining, agriculture and people’s livelihoods all depend on the fresh water that cycles through the alpine wetlands.
"This week’s TIME magazine
shares a series of photographs of melting and retreating glaciers from
northern Greenland, British Columbia and Iceland. I have just returned
from Chile, where glaciers are rapidly shrinking high in the Andes
Mountains. These glaciers provide an essential ecosystem service to
Chile through the provision and regulation of fresh water. Over the past
3 years, the country has experienced record drought – particularly in
the central regions where Chile’s enormously productive and economically
indispensable agriculture industry is based. Glacier and snow-melt
source the high Andes watershed, which feed the river systems that
eventually reach Chilean vineyards, fruit orchards and cereal crops. In
spite of the drought, water from these mountain glaciers has allowed
business to continue as usual.
This past week, Fauna & Flora International (FFI) visited Anglo American’s
Los Bronces copper mine where ore is extracted between 3,000 and 4,500
metres above sea level (above 10,000 feet). This is one of the world’s
largest and highest grade copper ore bodies. It is also one of the
highest mines in the world. Copper has been mined here for 200 years and
there is sufficient copper to continue mining for at least another 200
years. The ore body extends deep into the mountains, exposing
periodically where glaciers have cut the rock away.
Los Bronces lies within the San Francisco valley, adjacent to Dolores
and El Plomo valleys. The mine has completely altered the San Francisco
watershed – with a huge stoped hole, massive waste rock dumps, and an
old tailings dam. The El Plomo valley has been carefully explored and
holds a water storage facility for the operation, while the Dolores
valley lies in between, its fate uncertain.
The three valleys support a high alpine wetland system that provides
water to Santiago and to vineyards and farming communities in the
surrounding countryside. Sophisticated water management systems have
been created to divert water around the mine to ensure that water from
San Francisco valley can flow downstream uncontaminated by mining. The
water needed for mining operations is pumped from the northern Aconcagua
Basin (such romantic and dramatic connotations as Aconcagua is the
highest mountain in South America). Fresh water is used in the
copper-rich slurry that is piped 56 km to a concentrator and tailings
facility located 3,500 m below on the plains north of Santiago. A water
circulation process at these facilities maintains a neutral water
balance and water is kept out of the mine pit. Through this water
management system clean and “dirty” water are not mixed.
Mining operations at Los Bronces have essentially destroyed the
functioning of the San Francisco watershed. Activities in the Dolores
and El Plomo valleys have, however, been specifically designed to avoid
disruption to the natural ecosystem function of these valleys. To this
effect, pipelines have been constructed using design and technology to
determine routes that avoid negatively impacting wetlands and enable
natural sea pitch into ground water.
One of the most important sustainable water management measures at
the mine has been to develop a greater understanding of the role that
glaciers play as a source of water for the wetlands, which then gently
feed water into the rivers. The inconspicuous and fragile alpine
wetlands act as a sponge, and although they are not highly biodiverse
they have high endemism and are critical habitats for the ecosystem
services they provide. During the summer months, glaciers bleed water
into the wetlands providing a constant supply of water to quench the
demand of downstream users. During drought, the glaciers act as a water
store, maintaining water availability for millions of users.
For a mining operation, glaciers are dangerous and unpredictable
impediments to development. Both grey and white glaciers overlie Los
Bronces and the surrounding ore bodies which hold hugely valuable
resources. Chilean legislation currently prohibits the destruction of
glaciers – for good ecological and biophysical reasons! Even the
glaciers lying in the path of large mining operations are protected.
However, studies are now underway to better understand and predict
future glacier dynamics in the mountain-scapes surrounding Los Bronces.
Will mining have access to the land uncovered as glaciers retreat? What
will happen to the ecological value of glaciers and the ecosystem
function they support?
We worked with Anglo American this week to identify their
dependencies and impacts on ecosystem services. Together, we recognised
the extraordinary importance of water to the company and to all other
water users in the region. We were able to recognize along the entire
watershed profile the key habitats and species whose interaction with
water provisioning and regulating services demanded their careful
management and protection. We identified stakeholders who are
co-dependent on their resources and began to understand some of the
risks associated with the company’s operations and their role in the
landscape. Thinking 20, 50, even 100 years down the track, we asked the
questions which are hard to face: where will their water come from; what
will the impacts of a changing environment be; and how might their
licenses to operate, abstract water and harvest natural assets be
constrained?
We did not get to any final answers, but we did, however, realise
that solutions for the sustainability of both business and natural
resources are entirely interdependent – and that we need to think about
the unthinkable in order to do the necessary.
Anglo American – Copper
have embraced an ecosystem services approach. The Chilean Government is
in the middle of a process to integrate ecosystem services into their
legislation. They now demand those impacting the environment to
compensate their actions through biodiversity offsets.
For a company, the push-pull tension between regulatory compliance and
global best practice performance is generally won by compliance; often
to a national rather than global standard. This is extremely
disappointing. In Chile, I think we might finally have a context where
regulation is catching up and will now lead best practice for the
management of biodiversity and ecosystem services."
PIPPA HOWARD
Director
Director, Business & Biodiversity
Fauna & Flora International
Fauna & Flora International
(Published here with permission)