Dewatering permits are required when it is not possible to contain pumped water on site during construction activities (i.e. foundation excavation in shallow groundwater areas, swimming pool installations/liner changes, etc.), or to register residential sump pumps having permanent discharges into the street or Town of Islip drainage systems.

The attached documentation is required prior to Town Board acceptance of an easement when land is not being dedicated.

Step by step directions for filing Engineering Division applications electronically, including instructions on uploading documents.

For questions related to Engineering Division applications or inspections, please fill out the attached form and email it to This email address is being protected from spambots. You need JavaScript enabled to view it..

General guideline for applicants and contractors in understanding the inspection process for issued permits

When a dedication of land is proposed to the Town of Islip (e.g.: road widening, recharge basin, conservation area, corner radius), the attached documentation is required prior to the Town Board acceptance of the dedication.

Subdivisions of land involving the creation of a road or more than 5 lots.

Subdivisions of land involving the creation of up to 5 lots on an existing street.

When a dedication is proposed to the Town of Islip for a new public road resulting from a subdivision or road opening, the attached documentation is required prior to the Town Board acceptance of the dedication.

Creation of a new road or extension of an existing road.

All commercial, industrial, institutional, and multi-family planned unit developments are required to obtain site plan approval for conformance with all Town of Islip Zoning Ordinance Standards and Land Development Regulations prior to the issuance of any permits.

Effective July, 2020, Site Work Only Permits will be issued by the Engineering Division.

The Subdivision and Land Development Regulations contains helpful information regarding the Subdivision, Site Plan and Land Clearing process including design submission and improvement standards. This 2019 Amendment includes updates to the appendices. If you have any questions, please give our Engineering Division a call at 631-224-5360.