Toye Nullah Kohat.
Kohat division is a green valley surrounded by big green hills; tall trees and plants growing all around it. However there is no big river in the area, though a lot of streamlets flow here which are called Toye, Khwarr and Algadah in local dialect. Toye flows down winding through the hilly areas of upper Orakzai agency and west of the Hangu city. The Nasar Toye Nullah (Stream) joins the Toye near the village Raisan in district Hangu, thus it adds to its volume. The Nasar Toye also flows out from the mountains of the upper Orakzai (Ali khel).
At the village Usterzai, this Toye is joined by a streamlet which originates from the hilly areas of lower Orakzai and after passes through many areas it merges into Tanda Dam Kohat. Many creeks and rain water increase its volume. This stream flows from west to east wards, traverse the Hangu city and near th Nusarat khel (Kohat) one part of it falls into the Tanda Dam which turn falls into in River Indus, which flows about 40 km away from Kohat city. The Toye stream traverses a total distance of about 145 km.
The area through which the Toye (stream) passes and irrigates the fields was previously known as "Miranzai valley". The greenery of Kohat, Hangu and adjoining areas can be attributed to the Toye stream. Most of the area of Kohat and Hangu is actually arid and barren and the level of the stream is lower so therefore the Toye can't irrigate most of the land. For many decades the farmers dug canals from the Toye just to irrigate their orchards, fields and gardens. Moreover when it is heavily raining this Toye (stream) is flooded and sometimes its water overflow on the bridges made over the Toye, thus it blocks the routes at many places.
However the Toye is an important natural water resource and this water body renders a number of services and benefits to a man in many ways such as small Fish hunting, for domestic uses such as washing of clothes, utensils; moreover it is a main recharging source of Tanda Dam. It raises the underground water table of the surrounding areas.
The flow is generally observed the least in early summer and maximum in monsoon. Water of the stream in the upper areas has better quality as compared to the lower areas.
It is flooded in rainy season; its water is used for agriculture and irrigation as well. It takes away the sewage of the villages through which it flows; therefore most of the species of aquatic life can't prosper in it. However different kinds of Fish, Insects and Turtles, crabs, water beetles, Leeches, Moleskins and other invertebrates, hydrophytes etc are found in abundance. Here agriculture depends on rain. 62% of cultivable land is irrigated through rain water. Only 8 % of the land is irrigated through water from tube well, canals or other such sources. In Hangu 60% of the Land where wheat is cultivated is arid. That's why it's per acre yield is low
The surface water quality of the Toye stream is affected by both the anthropogenic activities and natural processes. Natural processes influencing water quality include precipitation rate, weathering processes, and sediment transport whereas anthropogenic activities include urban development and expansion, industrial and agricultural practices. These activities often results in the degradation of water quality, physical habitat and biological integrity of aquatic ecosystem. Increasing exploitation of water resources in catchments is responsible for much of pollution load. Children bathe in it, which can cause many serious water borne diseases such as Diarrhea, Dysentery, skin and eye allergies, rashes, cholera etc.
In ancient times its water was fit for drinking, but with the advancement of industry and technology, the people have started using bathrooms, latrines, human excreta and different drainage systems also linked with this canal. Long time ago, the life was very simple. Today the household materials/ items are very common; people use soaps and detergents for bathing and washing clothes; shampoos, creams, cleaners, acids, cosmetics, organic and inorganic items also produce dirt which ultimately fall into the stream and thus contaminate the water.
Adverse effects of physicochemical parameters on aquatic ecosystem may occur at all levels of biological communities can be wide-ranging or limited, temporary or permanent. Mainly serious effects involve loss in productivity, changes in growth, loss of primary productivity, altered diversity or community structure, changes in aquatic ecosystem process (such as nutrient cycling) and losses of valuable species. These ecological losses in turn may be economically, aesthetically, or socially important.
The Toye stream and their tributaries passing through Hangu and Kohat cities receive large amount of contaminants released from industrial, domestic/sewage, household and agricultural effluents which has resulted increasing degradation of fresh water ecosystem. Indiscriminate discharge of these effluents (either from industrial, municipal and agricultural activities, or heavy metals such as Arsenic, Mercury, Cadmium, Zinc, Lead etc on road and in the vicinity of vehicular workshops area) containing toxic substances into aquatic environment, creating problems of water pollution rendering water no longer fit for drinking, agriculture and aquatic life and thus finally destroy that particular aquatic habitat which contain rich biodiversity. Some of these effluents are toxic in nature while other has hazardous effect on aquatic wildlife.
Since then the household solid wastes, villages flush system and other forms of pollution have been disposed off into the Toye stream. As a result the local fish fauna and hydrophytes have started declining. These effluents as a group are diverse in nature.
Continuous discharge of effluents containing toxic substances into the aquatic environment is putting the integrity of streams and rivers at risk. Consequently the surface water of the Toye stream is facing the menace of environmental degradation. "BOD" (biochemical oxygen demand) and "COD" (chemical oxygen demand) values are imbalanced. Integrity and biological value of this stream is getting deteriorated from discharge of untreated municipal waste. No study has examined the spatial and temporal variation and identification of sources of pollutants the in Toye stream. Similarly no effort has been made to assess and monitor its surface water quality.
However, all is not gloom and doom. Reversing this trend is possible, as numerous conservation success stories have proven. Preserving biodiversity means preserving ourselves for it is the life support system for our planet. It is the direct source of our food, and the livelihoods of every one of us, in some way or another, depend on our planet's biodiversity, in the form of ecosystems, species and genetic material. Thus it is at the core of our quest for sustainable development.
Biodiversity impacts the quality these ecosystems are under threat from a variety of human activities. The transformation of habitats for human use, mostly agricultural, and overexploitation, including overgrazing, has led to the degradation and is an essential component to the sustainability of all human activity.
Certain studies and projects should be launched to pin point the locations and the targeted sources whose effluents are causing pollution in the Toye stream, and to determine the extent of pollution with special emphasis on the organic wastes and heavy metals in the stream and its evaluation for human use.
Research students and local scientists should know enough about the overall distribution of threats to the Toye biodiversity to be able to guide the allocation of this water resource to support biodiversity assessments and recommend direction for sustainable resource use.
Local people should know the identity and geographical distribution of its species is perhaps the most important information available in its attempts to preserve and use its biodiversity because if it is polluted in the same way a time will come when it will aesthetically and biochemically be degraded and dead.
The developed nations fully use their resources. The Almighty Allah has blessed the Bangash community with the precious gift of this Toye (stream) which is being squandered due to the ignorance of the people. It is the need of the hour that thorough research and watershed-management may be made on it so that it may be made useful for the poor inhabitants of Kohat and Hangu. the Toye nullah can be used for hydroelectric power generation , recreational purposes, for the development of industrial sectorand so many more areas, but unfortunately we haven't thought over it. It is a key of green revolution and prosperity of the area.
This short article highlighted the importance of an integrated effort for management, re-naturalization and restoration of Toye stream ecosystems and stresses the Importance to initiate concrete measures to control the indiscriminate discharge of industrial and municipal waste into the streams in order to preserve it from further degradation. Bold and everlasting steps should be taken to preserve that ecosystem; as it is a rich source of biodiversity.