Retaining Wall On Property Line Can A Developer Next Door To My Property Find A Legal Reason To Make Me Change The Grading On My Property?

Can a developer next door to my property find a legal reason to make me change the grading on my property? - retaining wall on property line

I live in Canada and a developer wants to build several villas, next to my property.
Are your plans at the same height as my home for the elimination of the hill built on my property.
The hill is wide and covered with flowers, flowering shrubs, a man streams, waterfalls and lakes on the hill, all together 15 to 25 feet, 6 to 8 feet high and 100 feet long.
The hillside property to its climax with the property line at the top of the hill. He told the people to remove the hill to build on the same level of my house, the city, you can delete this article?
If you were in a retaining wall on their side of the groundwater on their property less affected plants in mountain areas and put my water bill.
The mountain has over 50 years and have over the past 8 years for the way I'm happy.