Question: When did a project of further restoration and miantenance begin?
About the article "Notre Dame de Paris", section "Abstract".

Candidate passages:
In 2000, the Historical Hermitages Organization of Iran begin a restoration project of the Bazaar, with the full participation of the shop owners.
The rehabilitation project won the Aga Khan Award for Architecture in 2013. 
Such was the indignation of his subjects at the mistreatment of the castle that in 1827 the king, himself a Count of Vianden, repurchased the ruin for 1,100 florins hoping to begin restoration work.
Unfortunately, his time was taken up with the Belgian Revolution of 1830 and it was not until 1851 that Prince Henry of the Netherlands reconstructed the chapel at his own expense, giving it a lower roof.
When Adolphe of Nassau-Weilbourg became Grand Duke of Luxembourg in 1890, he charged Bobo Ebhardt, a German specialist, with further restoration.
Although Ebhardt succeeded in making important progress, his work was interrupted by the First World War.
During the Second World War, in the Battle of Vianden which took place on November 19, 1944, the castle was ably defended against the Waffen-SS by members of the Luxembourgish anti-Nazi resistance, and proved to have some military value even under conditions of modern warfare.
It was not until 1962 that consideration was again given to restoration, resulting in reconstruction of the Armory.
Further progress was hampered by questions of the castle's ownership.
Only after Grand Duke Jean had ceded the castle to the State in 1977 did work continue.
In 1978, attention turned to rebuilding the walls, the gables and the roof.
In 1979, the chapel was also given a new roof and restored to reflect its original Gothic appearance had been lost during the fire of 1667 caused by lightning.
The white tower was also reinforced and topped with a conical roof.
Finally, after the Nassau Mansion was fully restored in 1981–82, efforts were made to refurnish the interior as authentically as possible.
This work was completed in 1990. 
Successful restoration projects begin with careful study of the stream system, including the historical weather patterns, stream hydraulics, sediment transport patterns and related conditions.
Researchers evaluating restoration projects have found that many of these projects subsequently fail (e.g., with flooding or excessive erosion) because the projects were not designed with a sufficient scientific basis; restoration techniques may have been selected for aesthetic reasons.
The River Restoration Centre, based at Cranfield University, is responsible for the National River Restoration Inventory (NRRI) which is used to document best practice in river watercourse and floodplain restoration, enhancement and management efforts in the UK.
Other established sources for information on river and stream restoration include the National River Restoration Science Synthesis (NRRSS) in the United States of America, and the European Centre for River Restoration (ECRR) which holds details of projects across Europe, and in conjunction with the LIFE+ RESTORE project, is developing a ‘Wiki’-based inventory of river restoration case studies which is freely available to view online. 
The riparian forest restoration project was performed by the department of Center of Earth and Environmental Science (CEES) at Indiana University-Purdue University Indianapolis (IUPUI), and it is supported by the Lilly Endowment.
As a part of the riparian zone restoration project, 1400 trees were planted along the White River in downtown Indianapolis, Indiana.
After five years, the "Lilly Arbor Project" project will provide data on riparian zone reforestation strategies, which will be used in further research and future projects.
Students and faculty from various universities conduct research and maintain the restoration using the CEES service learning program. 
When an Act of Parliament was sought in 1965, to authorise the abandonment of the canal, the Inland Waterways Association petitioned against it, and when it was finally passed, it contained a clause that ensured the owners would maintain it until the adjacent Ashton Canal was abandoned.
In early 1971, a boat rally was organised on the canal, and later that year, there was public debate over the high cost of a project which had infilled part of the canal to create a shallow water park, when restoring the section for navigation would have been cheaper.
Discussion of the relative merits of restoring the canal or the Huddersfield Narrow Canal in 1973 led the formation of societies to promote both schemes in 1974.
The Rochdale Canal Society wanted to see the canal fully re-opened, as part of a proposed Pennine Park.
The Ashton Canal, which joins the canal above lock 84, reopened in 1974, and the nine locks on the Rochdale Canal between the junction and the Bridgewater Canal were restored at that time.
The canal benefited from the activities of the Manpower Services Commission in 1975, when £40,000 was allocated under the Job Creation Scheme to fund work on the Rochdale town section of the canal.
The following year, another 150 jobs were created when a further £208,000 grant was made.
Despite the progress, there were plans to sever the route with a low-level crossing by the proposed M66 motorway in 1979, and to build a supermarket on it at Sowerby Bridge in 1980, both of which were met with opposition.
One benefit of the Job Creation Scheme was that the perception of the restoration changed in official circles.
The local council was responsible for the young people employed on the scheme, which ran for twelve years, and found itself having to negotiate with the canal company.
At its height, there were 450 people working on the canal, and since no-one could work on the scheme for more than a year, several thousand people learnt practical restoration skills, and many retained an interest in canals afterwards.
The section from Todmorden to Hebden Bridge was completed in 1983, and opened on 20 May.
The Rochdale Canal Society worked hard both to protect the line of the canal and to begin the process of refurbishing it.
A new organisational structure was created in 1984, with the formation of the Rochdale Canal Trust Ltd, who leased the canal from the owning company.
A proposed extension to the M66 motorway created a new threat to the canal in 1985, but Greater Manchester Council began to look at ways to remove blockages in the following year, particularly the M62 embankment which blocked the route at Failsworth.
Calderdale Council managed a £1 million scheme to remove three culverts and restore two locks later that year, with some funding coming from the European Economic Commission.
The MSC-funded restoration was approaching Sowerby Bridge, where planners were proposing a tunnel and deep lock to negotiate a difficult road junction at Tuel Lane, so that a connection could be made with the Calder and Hebble Navigation.
The entire eastern section from Sowerby Bridge to the summit at Longlees was open by 1990, although it remained isolated from the canal network.
In 1991, an Ecotec Report looked at the costs and benefits of completing the restoration.
It estimated that another £15.9 million was needed, but for a total expenditure of £17.3 million, some £30 million of benefits would be gained by the region, including 1,028 full-time jobs.
Some of this money would come from Derelict Land Grants.
The re-fashioned link with the Calder and Hebble Canal (which had never closed) was funded by £2.5 million from this source.
The initial plan included a lock that was only long, but space was eventually found for a standard lock.
The first boat to pass between the restored Rochdale Canal and the Calder and Hebble Navigation did so on 11 April 1996, although the official opening did not take place until 3 May.
Tuel Lane Lock is nearly deep, making it one of the candidates for the deepest lock on the British canal system.
In 1997, the Rochdale Canal Trust was restructured, in response to announcements that there might be large grants available as part of the millennium celebrations.
The canal was still at this point owned by a private company, and the Millennium Commission would not make grants to a scheme which was for private profit, rather than public benefit.
The restructuring would allow the Trust to take over responsibility for the canal from the Rochdale Canal Company.
However, the plan was rejected by the Commission, and in order to access the grant of £11.3 million, the Waterways Trust took over ownership of the canal.
Additional funding to make up a £23.8 million investment package came from English Partnerships and the councils of Oldham and Rochdale.
As restoration proceeded, boats could travel further and further west, and the restoration of the sections through Failsworth and Ancoats were a significant part of the re-development of the north Manchester districts.
The restored sections joined up with the section in Manchester below the Ashton Canal junction, which had never been closed, and on 1 July 2002 the canal was open for navigation along its entire length.