The long-term average annual precipitation in Colombia is estimated at 3,240 mm, equivalent to 3,700 km³. Of this total, 58% becomes surface runoff, equivalent to an average flow of 2,145 km³/year or 1,879 mm/year. Therefore, with a flow of about 60 L/s per km², Colombia is one of the countries with the greatest natural supply of water in the world. This water flows through the five hydrographic areas of the country. The Amazonas basin contributes with 35%, the Orinoco basin with 28%, the Magdalena-Cauca with 14%, the Pacific with 14%, and the Caribbean with 8%.
According to the Food and Agriculture Organization of the United Nations (FAO) , total water extraction in 2015 reached 11,767 km³. The agricultural sector accounted for 54% (6,391 km³); 5,867 km³ for crop irrigation and 0.524 km³ for livestock raising. Municipal extraction reached 3,134 km³ (27%), 2,606 km³ of which were for households, and 0.528 km³ for the services sector. About 31% of the water used in the household sector were consumed in Bogotá city, 21% in Cali, and 19% in Medellín. The industry used 2,242 km³ of water or 19% of the withdrawals; 0.665 km³ of which were used for cooling thermoelectric power plants.
About 9% (1,073 km³) of all the water extracted, was groundwater and 10,694 km³ (91%) surface water. 75% of the groundwater used was consumed by the agricultural sector, 4% for livestock, 11% for municipal consumption, 6% for industry, and 4% for other purposes.
The major threats to the country's water resources are overexploitation of water sources and untreated or insufficiently treated wastewater discharges into water bodies from households, industries, mining operations, and agriculture effluents.
Key policies and governance approach
The National Policy for the Integrated Management of Water Resources (PNGIRH) set objectives, strategies, goals, indicators, and strategic lines of action for the management of water resources from 2010 to 2022. Its general objective is to guarantee the sustainability of water resources, through their efficient management and use linked to proper land-use planning and the conservation of the ecosystems that regulate water supply.
Specific objectives of the PNGIRH include (i) preserve the ecosystems and hydrological processes; (ii) characterise, quantify, and optimise water demands; (iii) improve the quality and minimise contamination of water; (iv) develop a comprehensive management of the risks associated with supply and water availability; (v) institutional strengthening for the integrated management of water resources.
SUCCESSES AND REMAINING CHALLENGES
The effectiveness of the Department-level Water Plans cannot be assessed. However, the extent of the ongoing implementation can be perceived: A total of 1,354 PDA infrastructure projects were implemented in 31 departments over the 2010-2017 period, with an estimated investment of approximately 647,378,517 euros.
Initiatives and Development Plans
The National Water Plan describes programmes, projects, and activities for implementing the National Policy for the Integrated Management of Water Resources (PNGIRH).
Various local-level, specific plans, known as “Departmental Water Plans”, have been formulated and are under implementation. These plans aim to harmonise the resources and implementation of efficient and sustainable schemes for the provision of residential public services of drinking water and basic sanitation. They take into account local characteristics, the institutional capacity of territorial entities and service providers and the effective implementation of regionalization schemes. Examples of Departmental Water Plans include:
- Guajira Azul - A programme aimed to increase the coverage and quality of drinking water and sanitation services in La Guajira department. Water service continuity in urban areas would be increased from 9 hours a day to 16, and coverage would increase from 4% to 70% in rural areas.
- Agua al Barrio - A strategy aimed to provide drinking water and basic sanitation services to populations in informal urban human settlements that currently do not have water 24 hours a day.
- Agua al Campo - A programme that seeks to close the gaps in coverage, continuity, and quality of water and sanitation services in rural areas.
- Conexiones Intradomiciliarias - A programme aimed at improving access to residential public water and sewage services, through the construction or improvement of intra-domiciliary and home connections when water and sewage services are technically required.
- Programa rural - Focused on water supply and basic sanitation services in rural areas, to reduce the gap with urban areas.
- Saneamiento de Vertimientos (SAVER) - SAVER seeks to structure integrated sustainable systems for wastewater treatment to increase the volume of urban wastewater treated, with a view to meet the goal set by the National Development Plan 2018-2022 of treating 54.2% of urban wastewaters by 2022, and 68.6% by 2030.
- Strategic plans for the country's five macro-basins (Magdalena-Cauca, Caribbean, Pacific, Amazon, and Orinoco) and 130 land-use planning and management plans for hydrographic basins are being prepared.
Although the effectiveness of Departmental Water Plans cannot be assessed yet, their customized character and the advances in implementation seem to be promising. However, financing the large investments needed for implementing these plans and for expanding them to other departments will be challenging, given the limited resources of departmental governments.
 FAO (2015). AQUASTAT Database. AQUASTAT Website