The Department is headed by a Director with five Divisions as follows:

1. Natural Ressources Management (NRM) ;
2. Environmental Planning and Assessment (EPA);
3. Pollution Control (PC);
4. Shoreline Protection and Reclamation (SPR) and
5. Flood and Erosion Control (FEC)

The function of the Department includes the following:
1. Formulation of Regional Environmental Policy, setting of Environmental Standards and Guidelines;
2. Development of Geographical Information System (GIS) database with appropriate maps depicting various levels of environmental degradation in the region
3. Development and implementation of effective strategies for restoring, conserving and protecting the environment and natural resources in the region.
4. Carry out Environmental Impact Assessment (EIA) of all major projects to be executed by MNDD in conjunction with the Federal Ministry of Environment.
5. Development and implementation of Memorandum of Understanding (MOU) between Ministry of Niger Delta Development and State Governments, Organizations and other relevant stake holders in Environmental related issues in order to avoid overlap.
6. Involving Interested Donor Organizations and Non-Governmental Organizations (NGO) in the environmental management of the region.
7. Implementation of International Conventions / Protocols/Agreements on the Environment in which Nigeria is a signatory.
8. Participating in Environmental Management Consultative fora at various levels.
9. Forestry Conservation and Restoration.
10. Tackling Climate Change issues
11. Control of Coastal and gully Erosion in the Region.
12. Pollution Control, etc.