The guarantee shall be sufficient in amount not to exceed 120% of the total cost to the Borough, as estimated by the Borough Engineer, of constructing those on-site, off-site and off-tract improvements necessary to protect adjacent property and the public interest in the event development of the subdivision or site were not completed. Such improvements shall include, but are not limited to, drainage facilities necessary to protect off-tract areas from flooding, erosion control and sedimentation control devices, required screening and fencing, all improvements within public rights-of-way, easements and the cost of seeding or otherwise stabilizing the site or subdivision, streets, grading, pavement, gutters, curbs, sidewalks, streetlighting, shade trees, surveyor's monuments, water mains, culverts, storm sewers, sanitary sewers, drainage structures, public improvements of open space and, in the case of site plans only, other on-site improvements and landscaping.