Blackwater River in Monaghan - is there two?

IrlJidel

I'm not a local but am trying to map some of Monaghan for Openstreetmap, which is a free wiki-like map of the world.

Monaghan (and the border-midlands area in general) isn't well mapped yet so thought I'd start adding some detail.

I'm drawing in some of the Blackwater River using Landsat Satellite imagery, and I am a bit confused. Are there two Blackwater rivers in Monaghan?

There's a Blackwater on the Monaghan/Tyrone border near Glaslough that starts near FiveMileTown then continues along the Armagh/Tyrone border to Lough Neagh.
http://www.openstreetmap.org/?way=29060278

Then there is a Blackwater that goes near Monaghan Town and continues to the Monaghan/Armagh border near Middletown.
http://www.openstreetmap.org/?way=75680619

Are these two rivers with the same name or are they the same river?
If they are seperate where does the 'Monaghan Town' Blackwater end and meet with the River Cor?

How do you distinguish the two rivers - do they have alternative names locally?

Upstream

I think they are two seperate rivers. The site below refers to them as the Monanghan Blackwater and the Ulster Blackwater.

http://www.fishingireland.net/fishing/salmonandtrout/dundalk/blackwatermap.htm

The Monaghan Blackwater rises near the Bragan mountains and flows in a south-easterly direction through Monaghan Town. It eventually joins the Ulster Blackwater Near Caledon.

There's a map of the Monaghan Blackwater there, but I didn't see a map of the Ulster Blackwater.

IrlJidel

Upstream wrote: »

I think they are two seperate rivers. The site below refers to them as the Monanghan Blackwater and the Ulster Blackwater.

http://www.fishingireland.net/fishing/salmonandtrout/dundalk/blackwatermap.htm

There's a map of the Monaghan Blackwater there, but I didn't see a map of the Ulster Blackwater.

Thanks for looking into this.

I found that site last night as well.

The 'Ulster Blackwater' is
http://www.openstreetmap.org/?way=29060278
and
http://www.openstreetmap.org/?way=29060294

The 'Monaghan Blackwater' is here:
http://www.openstreetmap.org/?way=75680619

From what I can gather the Monaghan Blackwater doesn't flow directly into the Ulster Blackwater. The Monaghan Blackwater flows into the River Cor here:
http://www.openstreetmap.org/?mlat=54.2877&mlon=-6.874&zoom=14&layers=M

The Cor then flows into the Ulster Blackwater.

(Any stretches of the river that are missing is due to clouds on the satellite imagery)

If I've mapped it wrong, please let me know.