The Department of Water, Irrigation and Environment which is divided into three Directorates namely;
a.    The Directorate of Water.
b.    The Directorate of Irrigation.
c.    The Directorate of Environment.

The Directorate of Environment has its own units that govern its performance.
A county where resources are sustainably harnessed and equitably shared for the benefit of every household.
Engaging all stakeholders in harnessing and governance of resources in a cost effective way for the transformation of the lives of the county’s population.

Pursuant to article 69 (1) (b) of the  constitution of Kenya it is an obligation of the County Governments to work towards achieving and maintaining a tree cover of at least 10% of the land area in Kenya. Article 42 of the constitution of Kenya, stipulates that, every person has a right to a clean and healthy environment, which includes the right to have the environment protected for the benefit of present and future generations through legislative and other measures. Article 69(g) directs the state to eliminate processes and activities that are likely to endanger the environment while article 70 gives guidelines on the prosecution of anyone violating the environmental law.
Gazette Supplement No.116 dated 9th of August, 2014 provides for devolution of specified forestry functions to County Governments including farm forestry extension services among others. The proposed Forest Conservation and Management Bill 2015, proposes for incentives for forests development by the County Governments in an effort to enhance livelihoods and reduce poverty for local people. It is on the basis of this, that the Directorate of Environment in Makueni County created a Forest Unit to ensure effective and efficient implementation of the Constitution of Kenya,2010 as per the aforementioned articles.
Forests provide a living for at least 1.2 billion people and nearly all of us consume some of the goods and services it provides. However, the forest cover all over the world has been dwindling and this is due to anthropogenic activities which threaten the existence of the forests. Forest destruction has been exacerbated by the increase in human population around the globe which has intensified the pressure on the already overburdened forests. The problem of forest destruction is not new in Makueni County and this has prompted the County Government through the Directorate of Environment to come up with and have a Forest Unit in her organogram to enhance conservation and sustainable management of forests, and forest resources. The environment directorate has hence committed itself towards the conservation of the forests at all cost. 
1.    Establishment of certified Agroforestry tree nurseries
A tree nursery is where plants are propagated and grown to a usable size either for commercial or domestic purposes. Tree nurseries form the basis of forests hence without tree nurseries we cannot have forests since tree seedlings are the building blocks of forests. To acquire healthy plants, it is good to give advice and help to farmers and provide to them any necessary assistance they may need to take care for the young plants as the basics of afforestation.

Establishment of certified agroforestry tree nurseries is basically to provide forestry materials (germplasm) on agricultural and shade trees. Forest Unit through collaboration with the Sub County Environment Offices initiated and established 20 Agro forestry tree nurseries, through provision of technical support among other things. The unit is also aiming in establishing 15 agroforestry tree nurseries in different wards in this financial year.
2.    Reforestation of hill forests
Forest Unit has been in the fore front in ensuring that Makueni County fulfils national constitutional requirement of 10% forest cover of the total area of land in Kenya. This has been done through ensuring reforestation is done in Makueni County. The Unit has been able to coordinate and ensure reforestation in the following Hill forests:
a)    Nzaui Hill forest
During the 2015/2016 FY, 58haIn 2015/16 FY, 58ha were replanted while in 2016/17 FY, 27Ha have been replanted making a total of 85Ha in Nzaui forest block.
b)    Katende Hill Forest
In 2015/16 FY, 35Ha were planted while in 2016/17 FY, 14Ha have been planted making a total of 49 Ha.
c)    Kyemundu Hill Forest
In 2016/17 FY, 14 Ha have been planted
d)    Yekanga hill reclamation
In 2016/17 FY, 1Ha has been planted and trenches have dug to reduce surface water run-off and conserve soil through prevention of soil erosion.
e)    Kibwezi Forest
In 2016/17 FY, 7Ha have been planted.
The forest unit has been able to assist the Government of Makueni County to do both reafforestation and afforestation to a total of 156 ha.

3.    Supply of seedlings to forest buffer zones
Buffer zones are areas in and around protected areas created to lessen biotic pressure and for the sustainable management of natural resources. The creation of buffer zones is aimed at motivating local communities in the participatory management of forest resources to fulfill their needs of forest products through the User Groups like community forest associations. The long-term objective is to gradually involve the local people in nature and forest conservation. In 2016/17 FY, the forest unit assisted in supplying 15,000 assorted seedlings to farmers around Nzaui, Makuli, Kyemundu and Kibwezi forests.
4.    Wote roadside tree planting
 Roadside planting helps in many ways like; to slow, absorb and clean water that runs of the highway resulting in reduced soil erosion, flood control and cleaner water supplies. They also provide important pollinator habitat adjacent to farm fields, orchards and vine green yards. In regard of these vital values of roadside tree planting, the Forest Unit aided in supply and planting of 5,000 tree seedlings along a section of in Wote town.
5.    Greening programs
The Unit has been able to plant 500 assorted tree seedlings in 7 earth dams in different wards and issued 500 tree seedlings to communities neighbouring such earth dam, giving a total of 7,000 tree seedlings. This has been done through collaboration with the Directorate of Internship, Mentorship and Volunteerism in Makueni County.
6.    Supply of seedlings to schools
This is an upcoming project I 2016/17 FY that will see five schools in each ward benefit from 170 assorted tree seedlings. This is geared towards achieving the ten percent forest cover in Makueni County.
Other achievements

Attending seminars, workshops and conferences e.g prospects of Biomass Energy in East Africa(ProBE) 
  • Coordination of issuance of permits and relevant forest licenses
  • Environmental awareness and sensitization on tree planting to different community members
  • Participating on anti-Eucalyptus planting campaign particularly in Mbooni sub county
  • Collaborating with other government agencies and institutions like TARDA and KFS in implementing relevant forest policies and laws
  • Daily office chores like attending to clients