This song is on Daoiri Farrell's new CD, A Lifetime of Happiness. I couldn't find the lyrics anywhere but did find this recording of Kevin Mitchell singing at the Trinity Inn in 1998.

Sweet Portadown (Trad. ?)

As I went out walkin' one morning in June,
I spied a fair damsel in the bright summer bloom,
Her cheeks were like roses, her hair it hung down
And she came from Blackwater near to sweet Portadown.

I stood in amazement as the breezes did blow,
And the blood in my veins like a river did flow
I thought her the fairest in all Ireland was found,
The day when I met her, near to sweet Portadown

Says I my we lassie, I don’t know your name,
She answered me shyly, I’m afflicted the same,
Says I mine's O’Connor, a name of renown,
She says mine's O’Driscoll from sweet Portadown,

I excused myself kindly, I said if you please,
We will both take a ramble in the Blackwater breeze
I’m sorry she said, but I can’t go today,
For I’m searching for young lambs, that have gone astray.

Then I will go with you, in search of your flock,
And the sun it did dazzle on her dark amber locks,
We searched the whole day, till the sun it went down,
And at length we located them near to sweet Portadown,

As we made our way homeward, we sat down to rest,
And we watched the rock thrush on the Blackwater cress,
I told her I loved her, as the sun went down,
Behind the green hills near to sweet Portadown,

She said if you love me, you must be excused
For I am a poor girl, so you must be refused,
I work hard for a living, the whole year around,
And besides I would never, leave sweet Portadown,

I won’t ask you to leave it, the place of your birth,
For I know it’s the grandest and fairest on earth,
But if you’ll consent for to be my own bride,
The it’s married we’ll be by the Blackwater side,

We went to her parents, they considered awhile,
Her mother looked on me, and at length she did smile,
If Flora consents, so we’ll consent to
And it’s married we were on the 18th of June

Come all ye fair maidens, assemble tonight,
And marry your first love, even though at first sight,
Don’t marry for riches or fame or renown,
For we living happy near to sweet Portadown.

I see some references to this song on Unionist pages, so assume this might be written by an Englishman. The lyrics are certainly similar (derivative?) of Mantle so Green and much cheerier than the other Black Water Side ballad. I can't put my finger on the tune Kevin is using.