Other affiliates	3 Months Ended
Mar. 31, 2013
Investments In and Advances To Affiliates, Schedule Of Investments [Abstract]
Investments in and Advances to Affiliates, Schedule of Investments [Text Block]	7. Other affiliates Mexico Affiliate In May 2010, the Company acquired, through its wholly-owned Netherlands subsidiary, Consolidated Water Cooperatief, U.A., a 50% interest in N.S.C. Agua, S.A. de C.V., (“NSC”) a Mexican company, and has since acquired the voting rights for, and an option to purchase, an additional 25% interest in this company. NSC has been formed to pursue a project encompassing the construction, operation and minority ownership of a 100 million gallon per day seawater reverse osmosis desalination plant to be located in northern Baja California, Mexico and an accompanying pipeline to deliver water to the Mexican potable water infrastructure and the U.S. border. The Company believes such a project can be successful due to what the Company anticipates will be a growing need for a new potable water supply for the areas of northern Baja California, Mexico and Southern California, United States. To complete this project, the Company has engaged two engineering groups with extensive regional and/or technical experience and has partnered with Doosan Heavy Industries and Construction (“DHIC”), a global leader in the engineering, procurement and construction of large seawater desalination plants. Once completed, a subsidiary of the Company will operate the plant while the Company will retain a minority position in its ownership. NSC is in the development stage, and is presently involved in (i) purchasing additional land on which to build the plant, (ii) seeking contracts for the electric power and feed water sources for the plant’s proposed operations, and (iii) conducting (under a Memorandum of Understanding with DHIC) an equipment piloting plant and water quality data collection program at the proposed feed water source. In addition to completing these activities, NSC will be required to complete various other steps before it can commence construction of the plant and pipeline including, but not limited to, obtaining approvals and permits from various governmental agencies in Mexico and the United States, securing contracts with its proposed customers to sell water in sufficient quantities and at prices that make the project financially viable, and obtaining equity and debt financing for the project. NSC’s potential customers will also be required to obtain various governmental permits and approvals in order to purchase water from NSC. For its 50% interest in NSC, the Company provided initial equity funding of $4.0 million for NSC’s development activities and has also provided all subsequent funding for NSC. Because the Company exercises effective financial control over NSC and its partners in NSC have not participated in NSC’s funding, the Company consolidates NSC’s results of operations. Included in the Company’s consolidated results of operations are general and administrative expenses from NSC, consisting of organizational, legal, accounting, engineering, consulting and other costs relating to NSC’s project development activities. Such NSC general and administrative expenses amounted to $479,307 and $341,327 for the three months ended March 31, 2013 and 2012, respectively, and totaled approximately $6.4 million for the three year period ended December 31, 2012. The assets and liabilities of NSC included in the Company’s consolidated balance sheet amounted to approximately $1,432,000 and $179,000, respectively, as of March 31, 2013 and approximately $1,452,000 and $116,000, respectively, as of December 31, 2012. In February 2012, the Company acquired an option, exercisable through February 7, 2014, to purchase the shares of one of the other shareholders of NSC along with an immediate power of attorney to vote those shares. As a result, the Company has effective control of NSC until this option expires. In July 2012, NSC obtained an extension of the purchase contract for a portion of the land on which the proposed plant would be constructed. In exchange for additional prepayments of (i) $500,000 paid at signing of the extension and (ii) a further $500,000 payable on May 15, 2013, NSC was granted an extension of the purchase agreement until May 15, 2014. NSC is currently negotiating a purchase agreement for an additional parcel of land. In August 2012, NSC and DHIC extended their Memorandum of Understanding for 18 months from August 19, 2012, pursuant to which DHIC installed and is operating an equipment piloting plant and collecting water quality data from the proposed feed water source site in Rosarito Beach, Baja California, Mexico. This amended Memorandum of Understanding requires that NSC negotiate exclusively with DHIC for the construction of the 100 million gallon per day seawater reverse osmosis desalination plant and further requires payment by NSC to DHIC of up to $500,000 as compensation for the operation and maintenance of the equipment piloting plant should NSC not award the engineering, procurement and construction contract for the project to DHIC. In November 2012, NSC signed a letter of intent with Otay Water District in Southern California to deliver no less than 20 million and up to 40 million gallons of water per day from the plant to the Otay Water District at the border between Mexico and the United States. NSC has entered into a 20 year lease, effective November 2012, with the Comisión Federal de Electricidad for approximately 5,000 square meters of land on which it plans to construct the water intake and outtake works for the plant. The amounts due on this lease are payable in Mexican pesos at an amount that is currently equivalent to approximately $20,000 per month. This lease is cancellable should NSC ultimately not proceed with the project. The Company has determined that completing NSC’s development activities will require significantly more funding than has been expended to date and the Company may incur significant development expenses in the future for this project. The Company estimates that it will take at least through the second quarter of 2014 for NSC to complete all of the development activities (which include completing the site piloting plant activities, purchasing the land for the plant, securing feed water and power supplies, completing the engineering and feasibility studies, negotiating customer contracts, obtaining required regulatory permits and arranging the project financing) necessary to commence construction of the plant. However, NSC may ultimately be unable to complete all of the activities necessary to begin construction of the project.

Other affiliates

3 Months Ended

Mar. 31, 2013

Investments In and Advances To Affiliates, Schedule Of Investments [Abstract]

Investments in and Advances to Affiliates, Schedule of Investments [Text Block]

7. Other affiliates

Mexico Affiliate

In May 2010, the Company acquired, through its wholly-owned Netherlands subsidiary, Consolidated Water Cooperatief, U.A., a 50% interest in N.S.C. Agua, S.A. de C.V., (“NSC”) a Mexican company, and has since acquired the voting rights for, and an option to purchase, an additional 25% interest in this company. NSC has been formed to pursue a project encompassing the construction, operation and minority ownership of a 100 million gallon per day seawater reverse osmosis desalination plant to be located in northern Baja California, Mexico and an accompanying pipeline to deliver water to the Mexican potable water infrastructure and the U.S. border. The Company believes such a project can be successful due to what the Company anticipates will be a growing need for a new potable water supply for the areas of northern Baja California, Mexico and Southern California, United States. To complete this project, the Company has engaged two engineering groups with extensive regional and/or technical experience and has partnered with Doosan Heavy Industries and Construction (“DHIC”), a global leader in the engineering, procurement and construction of large seawater desalination plants. Once completed, a subsidiary of the Company will operate the plant while the Company will retain a minority position in its ownership. NSC is in the development stage, and is presently involved in (i) purchasing additional land on which to build the plant, (ii) seeking contracts for the electric power and feed water sources for the plant’s proposed operations, and (iii) conducting (under a Memorandum of Understanding with DHIC) an equipment piloting plant and water quality data collection program at the proposed feed water source. In addition to completing these activities, NSC will be required to complete various other steps before it can commence construction of the plant and pipeline including, but not limited to, obtaining approvals and permits from various governmental agencies in Mexico and the United States, securing contracts with its proposed customers to sell water in sufficient quantities and at prices that make the project financially viable, and obtaining equity and debt financing for the project. NSC’s potential customers will also be required to obtain various governmental permits and approvals in order to purchase water from NSC.

For its 50% interest in NSC, the Company provided initial equity funding of $4.0 million for NSC’s development activities and has also provided all subsequent funding for NSC. Because the Company exercises effective financial control over NSC and its partners in NSC have not participated in NSC’s funding, the Company consolidates NSC’s results of operations. Included in the Company’s consolidated results of operations are general and administrative expenses from NSC, consisting of organizational, legal, accounting, engineering, consulting and other costs relating to NSC’s project development activities. Such NSC general and administrative expenses amounted to $479,307 and $341,327 for the three months ended March 31, 2013 and 2012, respectively, and totaled approximately $6.4 million for the three year period ended December 31, 2012. The assets and liabilities of NSC included in the Company’s consolidated balance sheet amounted to approximately $1,432,000 and $179,000, respectively, as of March 31, 2013 and approximately $1,452,000 and $116,000, respectively, as of December 31, 2012.

In February 2012, the Company acquired an option, exercisable through February 7, 2014, to purchase the shares of one of the other shareholders of NSC along with an immediate power of attorney to vote those shares. As a result, the Company has effective control of NSC until this option expires.

In July 2012, NSC obtained an extension of the purchase contract for a portion of the land on which the proposed plant would be constructed. In exchange for additional prepayments of (i) $500,000 paid at signing of the extension and (ii) a further $500,000 payable on May 15, 2013, NSC was granted an extension of the purchase agreement until May 15, 2014. NSC is currently negotiating a purchase agreement for an additional parcel of land.

In August 2012, NSC and DHIC extended their Memorandum of Understanding for 18 months from August 19, 2012, pursuant to which DHIC installed and is operating an equipment piloting plant and collecting water quality data from the proposed feed water source site in Rosarito Beach, Baja California, Mexico. This amended Memorandum of Understanding requires that NSC negotiate exclusively with DHIC for the construction of the 100 million gallon per day seawater reverse osmosis desalination plant and further requires payment by NSC to DHIC of up to $500,000 as compensation for the operation and maintenance of the equipment piloting plant should NSC not award the engineering, procurement and construction contract for the project to DHIC.

In November 2012, NSC signed a letter of intent with Otay Water District in Southern California to deliver no less than 20 million and up to 40 million gallons of water per day from the plant to the Otay Water District at the border between Mexico and the United States.

NSC has entered into a 20 year lease, effective November 2012, with the Comisión Federal de Electricidad for approximately 5,000 square meters of land on which it plans to construct the water intake and outtake works for the plant. The amounts due on this lease are payable in Mexican pesos at an amount that is currently equivalent to approximately $20,000 per month. This lease is cancellable should NSC ultimately not proceed with the project.

The Company has determined that completing NSC’s development activities will require significantly more funding than has been expended to date and the Company may incur significant development expenses in the future for this project. The Company estimates that it will take at least through the second quarter of 2014 for NSC to complete all of the development activities (which include completing the site piloting plant activities, purchasing the land for the plant, securing feed water and power supplies, completing the engineering and feasibility studies, negotiating customer contracts, obtaining required regulatory permits and arranging the project financing) necessary to commence construction of the plant. However, NSC may ultimately be unable to complete all of the activities necessary to begin construction of the project.