This report is one of a series of Technical Reports on alluvial mining
in developing countries, most of which relate to Jamaica (see Preface
for details). They are the output from the 'Effective Development of
River Mining' project which aims to provide effective mechanisms for
the control of sand and gravel mining operations in order to protect
local communities, to reduce environmental degradation and to facilitate
long-term rational and sustainable use of the natural resource base. The
work was carried out under the Department for International Development
Knowledge and Research programme, as part of the British Government's
programme of aid to developing countries. The project was undertaken in
collaboration with key organisations in Jamaica and Costa Rica, who
provided field guidance and local support
In recent years, land-use conflicts, environmental restrictions,
resource depletion and a desire for consistent supplies of high quality
aggregates in Costa Rica have resulted in changes to the pattern of
supply of aggregates, with increased contributions of alluvial sand and
gravel from instream extraction (alluvial mining).
In Costa Rica, alluvial mining represents a source of good quality sand
and gravel with wide distribution, practically inexhaustible resources,
easy extraction, and simple processing requirements. However, their
generally distant location from the Great Metropolitan Area and the high
costs of transportation, limit resource development. Nevertheless, there
are many rivers which supply sand and gravel, particularly in the
Atlantic region. Distribution is mainly by lorry, but some material from
the Barranca river is also transported to San Jose by the recently
reopened railroad system.
Alluvial extraction in Costa Rica is carried out by numerous small
companies using unskilled or semi-skilled labour. Quarry operations have
a short life involving simple extraction and processing procedures. This
report describes the environmental impacts associated with the mining,
processing and transportation of alluvial sand and gravel in Costa Rica.
In Costa Rica, a specified volume of material may be extracted from a
river, based on calculations of the material that potentially could be
replenished, a concept termed the 'replacement volume' or 'dynamic
reserves' of the river. However, currently a standardised systematic
procedure for calculating such volumes does not exist.
The concept of 'environmental recovery' is considered as a means of
systematic control of the river mining operations. Mineral licences
should identify and execute mitigation measures which favour processes
of natural regeneration or recovery, diminishing negative impacts on the
environment. However, in areas of alluvial mining activity in Costa
Rica, restoration schemes are uncommon. The most relevant experiences of
alluvial recovery have been developed by the Costa Rican Institute of
Electricity (ICE) during the construction of hydroelectric power plants.
Based on these experiences, ICE specialists have listed a number of
activities which need consideration and whose prioritisation depends on
the stage of the development (before extraction, during extraction, and
post extraction) and on the particular environmental conditions of each
The report also presents a review of current mining and environmental
legislation in Costa Rica including specific alluvial mining
legislation, the management structure regarding alluvial mining
licences, and the requirements for environmental impact studies.
Recommendations propose future regulatory reform and improved management
practices in order to promote the alluvial extraction industry.
This report is available to download in full colour (6142 kb) and in
black and white (6142 kb).
F Alvarado-Villalon; Harrison, D.J.; Steadman, E.J. River mining: alluvial mining of aggregates in Costa Rica. (CR/03/050N). (2003)
River mining: alluvial mining of aggregates in Costa Rica. (CR/03/050N).