Retaining wall in garden public path way on the other side

Hi the design for the retaing wall will depend on mainly on the hight and load of what material is being retained. To not disturb the parth way behind the wall an L shape wall will need casting/building. With the toe side on your land with enough depth that the material placed on top will give a sufficient load to create a cantilever effect. Retaining the bank behind. Soly depends on load placed behind wall and high of bank being retained, to determine materials and design required.

Any structure providing support to an adopted highway ( path) becomes the responsibility of the local authority and would be to their design and construction , it’s in the Highways act . The path may have live services in it which you could disturb at major cost. Any subsidence of the path would be damage to a highway , a criminal offence under the same act , again big costs to put right . Thing to do is to imagine a 45deg angle down from the edge /surface of the path onto your property , and do not dig any deeper , this will ensure the integrity of the path and your duty , under the party wall act to provide support to it ,any thing else will get very costly to do correctly . Peter R. —ex highways adoption engineer of 30 years

You shouldn’t be asking on here as each job will need to be looked at on it’s own merits, you need to be consulting a structural engineer.