First half tries from flanker Ronny Kynes, No 8 Cameron Regan, full back Dan Haymond and wing Wes Cunliffe ensured their successful defence of the title courtesy of the four try bonus point.
Ebbw showed they have some powerful and mobile forwards and demonstrated good handling and running skills despite the poor conditions.
Former Wales Under 20 lock Ashley Sweet added a fifth try before the break, there was a penalty try on 60 mins and centre David James finished off some slick play to cross in the corner five minutes before time.
Right wing Cunliffe crossed in the final play of the game and Smerdon kicked his fifth conversion of the match to take the score to 50-7 and enable the north Gwent side to celebrate their league victory in style.
Beddau's only score was an early try for centre Rhys Lott converted by Dion McKintosh.
Ebbw Vale Club Captain Damien Hudd said: "It's a massive day for us. We've worked so hard for this for the past four years and it's finally paid off. Being promoted makes a big difference to valleys rugby and it means a lot to us".
Head Coach Jason Strange added: "I'm a big believer that you end up where you're meant to be eventually. My number one objective when I re-joined the club was to get us promoted. It's taken four years but we're there now. I'm delighted for the players who have sacrificed so much to get us to where we are today and I think we've proven that we deserve our place in the Premiership".
WRU Board Member Ken Hewitt, added: "It's a fantastic achievement for Ebbw Vale and it's especially positive for north Gwent as the club acts as a catalyst to attract youngsters to the game. The brand of rugby that they playing at the moment and the players that they are developing have already secured success in terms of support in the area".
Ebbw Vale scorers: Tries: Kynes, Regan, Haymond, Cunliffe (2), Sweet, pen try, James; Cons: Smerdon (5)
Beddau scorers: Try: Lott; Con: McKintosh