I wouldn't consider Odiáxere to be close to the Barragem de Bravua lake, its actually 9km distant. What I do find coincidental however is that Odiáxere features earlier in this case as it was there that the two GNR officers who attended Madeleine's disappearance were originally investigating a suspected breaking and entry when the call came for them to go to Praia da Luz.
Could these two incidents be connected?
Yes they could be connected. I would liked to have seen the June letter in the files. They needed cadaver dogs in that search. The lake is an obvious spot close to Luz. The gardener said the letter he found had Madeleine Beth McCann written on it.
Wednesday 06 June 2007 Kate and Gerry's exit from Berlin is delayed when the Portugese police say they have received some information that they need to be consulted on. Gerry dismisses this as 'nothing of interest' and it means they miss 2 TV programmes due to arriving in Amsterdam 3 hours late.
They do manage to find time to catch up briefly with a few old friends from the time they spent in Amsterdam.
Thursday 07 June 2007 After the scheduled meetings, Gerry catches up with 'a friend of mine who was attending a medical conference in Amsterdam'. It is speculated that this was Matthew Oldfield who is believed to have been attending the Euromedlab 2007 event in the city at that time. See figure on the left of picture below.

Monday 11 June 2007 An anonymous letter and map are received in the offices of The Telegraaf, a Dutch newspaper, which claim to show where Madeleine is buried. The reporters immediately contact police and hand over the documents. A decision is made not to publish the map or hand it over to third parties.
Thursday 14 June 2007 Initial searches of scrubland indicated by the letter to The Telegraaf do not reveal anything unusual.
Friday 15 June 2007 Police with sniffer dogs search scrubland 9 miles from Praia da Luz where Madeleine's body is reported to be but the hunt is called off after only 4 hours. Extensive search finds nothing but a towel.
"The information indicated an area 15km from the place of the disappearance of the little child.
Barragem de Bravua to apartment 5A = 13.2km
Letter searches to apartment 5A = 13.75km
Letter searches to Barragem de Bravua = 5-6km