The National Environment Management Authority (NEMA), is established under the Environmental Management and Co-ordination Act No. 8 of 1999 (EMCA) as the principlal instrument of Goverment for the implementation of all policies relating to environment . EMCA 1999 was enacted against a backdrop of 78 sectoral laws dealing with various components of the environment, the deteriorating state of Kenya's environment, as well as increasing social and economic inequalities, the combined effect of which negatively impacted on the environment. The supreme objective underlying the enactment of EMCA 1999 was to bring harmony in the management of the country's environment.

Mandate of NEMA
Section 9(i) of EMCA mandates the Authority to exercise general supervision and coordination over all matters relating to the environment and to be the principal instrument of the Government of Kenya in the implementation of all policies relating to the environment.
The Authority is a Semi Autonomous Government Agency (SAGA) in the Ministry of Environment, Water and Natural Resources and has been in operation since 1st July 2002. The Authority works closely with lead agencies and development partners, the latter who include UNEP, UNDP and DANIDA. Since its establishment NEMA has implemented three strategic plans and has been on performance contracting as required by the State Corporation (performance contracting) Regulations, 2004 legal notice No. 93. Under these regulations, Boards of Directors in state corporations, among others, are required to sign performance contracts with the Government, against which they are periodically evaluated.