Performance guarantees shall be submitted in favor of Corbin City in an amount not to exceed 120% of the cost of installation for improvements it may deem necessary or appropriate including: streets, grading, pavement, gutters, curbs, sidewalks, street lighting, shade trees, surveyor's monuments, water mains, culverts, storm sewers, sanitary sewers or other means of sewage disposal, drainage structures, erosion control and sedimentation control devices, public improvements of open space and, in the case of site plans, other on-site improvements and landscaping. Ten percent of the total performance guarantee shall be in cash deposited with the City Clerk and the remaining 110% in a form acceptable to the City Attorney. They may be usable at any point by the City for the non-performance of the applicant. Such guarantees shall run for a period of 24 months, subject to extension by the City Council.