Using various types of broadly classified and large-scale data, the Ethiopian Construction Design and Supervision Works Corporation (ECDSWC) provides professional services such as engineering studies and design. Storing, managing, and sharing datasets within workgroups and research teams was not an easy task before the corporation implemented the data portal. To resolve the issues related to data management, this study provides a secured and modular data portal by implementing REST API principles. The data portal is used to manage a wide variety of datasets, such as spatial data and their attributes, along with metadata and other serialized documents that support the business operation of the corporation. On the top of data management strategies, the Security in Depth (SiD) mechanism is developed by implementing the Unified Identity Authentication Service, which provides a multilayered security scheme. The applicability of the data portal is demonstrated using datasets obtained from ECDSWC. Further, the accuracy, integrity and privacy of the data are evaluated, and system performance is weighed through a prepared test case.