The dunes of Putu are 22 kms north of Constitution in the Maule region. Include 38 kms its totality along the beach, and constitute a natural barrier that separates the people of Putu from the sea, stabilizing local climatic conditions, such as rains and temperatures, avoids catastrophes if there are earthquakes and tsunamis, at the same time Recharge underground aquifers in the area. The affected area also includes wetlands that concentrate 40% of the 240 species of fauna existing in the Maule region, and houses hundreds of migratory birds .
In January 2010 the company Inversiones Aconcagua S.A Chilean subsidiary of the Australian firm South American Iron & Steel, achieved the concession and the right to exploit the area. Thus, he signs an agreement with the company China Sinotech to exploit lithium, titanium, vanadium and iron that are in the same enclosure. The calculations amount to 823 million tons of iron sand, which would affect the extent of the dunes and wetlands located behind the Dunaria line at the coastal edge. On the other hand, the company registers measurements on the populated territory that has yielded significant concentrations of ore, which allowed to infer risk of future expropriations in inhabited areas. There are currently permits granted for exploitation in the Junquillary area, south of Putu, and a request from other new equivalents at 1200 Hás at the North Maule. The total concessions is 21,000 Hás. (91 polygons) on behalf of different people but correspond to the same project .
The speed with which the state delivered the concession aroused the suspicions of parliamentarians In the area, and generated a broad citizen movement, between these, the group of defense and conservation Maule-Mataquito (ADEMA) that works to this day. Likewise, the issue of concealment of the company's efforts and the lack of citizen consultation generated discomfort among opponents. The demarcation milestones appear suddenly in the area, without permissions and without the people of Putu could realize when they were installed. Among all generated actions, road cuts and dissemination of information through the media, and initiated a movement to declare the dunes of Putu as a Sanctuary of Nature 
In January 2011, the Commission of Natural Resources sent control trades to the Ministry of Education, Environment, Regional Undersecretary of the Maule Environment, Council of National Monuments, the Intendance of the Maule Region and the Municipality of Constitution . In document the parliamentarians ask for a response that explains why the process of declaration of Natural Sanctuary  was paralyzed. 0 code>
In the opinion of the DC Pablo Lorenzini the delivery of The concession to Aconcagua S.A. It was due to the desolation and lack of concern of the authorities for protecting environmental and tourist interests. On April 10, 2013, in a unanimous manner, by 75 votes, the Chamber approved the draft Agreement No. 762, which asks the Executive to protect the Putu wetlands, leaving the great environmental impact that the commune will suffer. For this reason, the deputies requested that the feasibility of declaring these wetlands as a sanctuary of nature and thus stop the mining extraction process .
the 6 From August 2013, the Talca Court of Appeals admitted a resource of protection against the project and issued an order not to innovate, ordering that prospective tasks be paralyzed in the area. Led by the mayor of Constitución, Carlos Valenzuela, the deputy Pablo Lorenzini and the group Adema, the neighbors accused the company Southeamer Iron & Steel of being conducted an 'aggressive, unauthorized and unconsultant intervention' on the dunes of Putu  .
Finally, the year 2017 The Putu wetland was praised as a sanctuary of nature .
Keywords: Dunes, Costal Areas, Mining, Natural Protected Areas ..