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GOVERNMENT
OF ANDHRA PRADESH (FOREST DEPARTMENT)
SRI S.K. DAS,
I.F.S., PRINCIPAL
CHIEF CONSERVATOR OF FORESTS ****
CIRCULAR
No.5/2002/PMU-I/3
Sub: NEERU-MEERU Works Water shed treatment of area Saturation Level treatment Andhra Pradesh Community
Forest Management Community Participation in Management
of Forests Integration of Programmes Creation of durable assets
capable of generating Income and employment -Certain guidelines Issued Regarding.
* * * The Government
of Andhra Pradesh have taken up a massive Water-shed programme
under Neeru-Meeru since May 2000 giving a lot of importance
to community participation in it in order to conserve scarce water
resources which is the surest way to prosperity.
The Forest Department of Andhra Pradesh has accordingly
taken up Soil and Moisture Conservation (SMC) works in the form
of Continuous Contour Trenches (CCTs), Staggered Trenches, Rock
Fill Dams, Check Dams and Percolation Tanks etc. 2. The Forest
Department of Andhra Pradesh has also implemented the Phase-I
of Andhra Pradesh Forestry Project (APFP) from 1994 to September,
2000, funded by the World Bank wherein the community participation
in regeneration of degraded forests has been the main component. 3. Although
the implementation of the Neeru-meeru programmes in the forest
area has been satisfactory in general given the allocation of
budget, the task assigned and the understanding of the situation
prevailing at the time of starting the programme,
however, after implementation of the project over a period
of more than two years
in the department and for a period of four years by the undersigned
in the Forest Development Corporation and after a close interaction
with Sri T. Hanumantha Rao, Chairman, Technical Committee, Water
Conservation Mission, I am of firm conviction that what we are doing for harvesting the water in our forest
areas by digging CCTs and erecting Rock Fill Dam/Check Dam/Percolation
Tank, is hardly good enough to impound 5 to 10% of the available
water. This has been once again reiterated by Sri
T. Hanumantha Rao when he addressed the Conservators of Forests
and other senior officers of the Department on 03.08.2002 in the
Committee Hall of PCCFs office. 4. In view
of what he has presented on that day which is supported by supply
of technical papers and in order to enrich the VSS area with forests
and water resources with far reaching consequential benefits to
the society, the following guidelines are issued:-
(1)
The VSS area should be demarcated for the purpose of Watershed
with the concept of ridge to valley. The VSS area may have one
watershed or more than one watershed or may be even a part of
a watershed.
(2)
Once the watershed area is demarcated on the ground and marked
on topo-sheet, the water flow stream should be identified. The water flow stream may be of 1st
order, 2nd order, 3rd order etc. The 1st
order stream is one which begins at the upper slope of the watershed
area and generally the depth of it is quite shallow
whereas the 2nd order stream
is the confluence of two 1st order streams. Similarly the 3rd and 4th
order streams.
(3)
Once all the streams 1st order, 2nd
order, 3rd order etc., are identified in the watershed,
action should be taken from the 1st order stream first
for harvesting of available rain water by erection of earthen
bund or and sunken gully pits. In general we will dispense with the Rock Fill
Dam (RFD) as it is not so cost effective for harvesting water
compared to other structure.
(4)
In the first order stream the earthen bund may be a very small
one having a catchment area of only 5-10 hectares. The following steps should be taken to erect
the earthen bunds:- Scrapping of the earth to a depth of 10 cm 15 cm and a width
of 2 mt or more on the site of the construction of the earthen
bund should be done first and
this soil should be kept in a separate heap to be utilized
at the end of the formation of the bund for spreading over the
bund so that the top soil which contains a number of grass seed
and seed of other species will germinate on the top surface of
the bund which will prevent the soil erosion. A typical design
of the bund is given below. It may be seen from the design on
one side of the bund there is a passage for water to spill over
the bund. This is called by-wash which is 30 cm to 100 cm lower than the level
of the bund depending on the size of the bund and this is absolutely
necessary for the survival of the bund.
(5)
Sunken Gully Pits: Sunken Gully Pits are trenches excavated
across the Gullys of 1st order and 2nd order
streams in order to impound water in the trenches. The dug out earth may be kept in the trapezoidal shape at
a distance of 50 cm (berm) from the trench giving a passage of
water as in earthen bund and seed of Kanuga, Seethaphal and Neem
may be sown on the dug out earth. The frequency or the interval between two Sunken Gully Pits
will depend on the slope more the slope more the number of such
Sunken Pits. After every 3 Sunken Gully Pits,
one silt trap pit may be provided covering gully which may be of the size of width of the Gully
x 1m x depth (60 cm). De-silting has to be done to these Gully Pits by the VSS members
and silt may be applied
to NTFP plants.
(6)
2nd Order Stream: The method of the treatment of 2nd order stream
will be almost the same as given in the 1st order stream.
The only difference here will be that the construction
of the earthen bund may be of higher diemnsion.
(7)
3rd & 4th Order Stream: These are to be treated with erection of big earthen bunds
may be in combination
with only few check dams, when it is considered a dire necessity. In fact, there is hardly any need for construction
of any check dam.
(8)
There is a very common but false apprehension in the minds
of many that earthen bunds are weak and may give away at the time
of monsoon due to the force of flowing water.
In this regard it has to be remembered that the famous
reservoirs like Nagarjunasagar and Cumbum tanks in Andhra Pradesh
are constructed with earthen bunds and the beauty of the earthen
bund is that with the passage of time the bunds become stronger
while in case of check dam with the passage of time it becomes
weaker.
(9)
The other obvious but significant advantage of earthen bund
is that at the time of erection of earthen bund, seeds of useful
NTFP species like Kanuga, Palymarah and Neem can be dibbled which
come up very well in such freshly dug up soils.
A typical cross section
of the earthen bund is also given.
(Drawing I)
(10)
The most important factor is that while
designing the water harvesting structures, the quantity of available
rain water should be calculated first and according to the available
quantity of rain water the water harvesting structure in the form
of percolation tank, sunken gully pits etc. should be planned,
designed and erected. In order to make the above points very clear
a simple example is given below:
(a) Total Watershed area
100 hectares (b) Annual rain fall
600 mm. (c) Water loss due to percolation = 10% = 60 mm (d) Water loss due
to evaporation & others = 50%
= 300 mm (e) Rain water available as run off = 240 mm (f) Total quantity of available water in 100 hectares = 10,000
m2 x 100 x 0.24 m
= 24,000 m3
(11)
From the above, it is seen that the
total quantity of available water which may be impounded in this
watershed is equal to240000 cubic metre. The facts from hydrology
about the capacity of the different types of water harvesting
structure in a rainy season are that CCTs will get filled in 10
times, percolation tanks 4 times, check dams 4 times. Our water
harvesting structure should be designed to impound 100% of this
quantity, and equally important is that it should start from upper
reaches of watershed to lower reaches uni-formaly spread over
the area almost up to the boundary point of the RF block.
Up to a depth of 500 m from the boundary of the RF in the
lower reaches of the watershed,
big percolation tanks should be constructed invariably so that
over a period of time these percolation tanks will naturally become
perennial. Drawing II will illustrate the above points.
(12)
Once the area is totally treated with
watershed the important programme like raising of valuable NTFP
species plantations at the lower side of the watershed should
be taken up in a planned manner for a period of 5 10 years in
order to augment the income to the members of the VSS and improve
the composition of the species in quality.
The whole idea is to convert unused /over used eco-system
in to durable assets capable
of generating income and employment to the VSS members and to
the local people. Let us assume that the available area at the lower side of
the watershed for raising valuable NTFP species plantation is
100 hectares where there is no
valuable tree growth.
This area can be divided into several sectors for raising
valuable NTFP species plantations and clonal plantations of Eucalyptus,
Bamboo, Teak etc. The espacement of NTFP plantation is generally
large i.e. 5 M x 5 M, 7 M x 7 M, 10 M x 10M, and therefore the
intermediate space can be utilized for raising medicinal plants.
While choosing the NTFP species, the following species may be
preferred.
(1)
In agency area Tapasi ( Sterculia urens
) should be raised.
Jack trees are also very popular / common
(2)
Usiri graft or seed origin (amla)
(3)
Kunkudu (Soapnut)
(4)
Kanuga (Pongamia)
(5)
Neem
(6)
Nerudu (Jamun) Only in case
of Seethaphal, the espacement
may be 3 M x 3M
(13)
The above plantations should be raised
in a series i.e. every year @ one hectare less or more for a period
of five years or more in a contiguous patch for each species. Similarly, the Eucalyptus clone, Teak, Bamboo
etc. may be raised in a series for a period of 5 10 years.
(14)
It should be noted here that once the
area is treated with watershed at saturation level as outlined
above, a few percolation tanks at the valley site of watershed
will definitely become perennial water sources and therefore the
VSS members will be in a position to take up watering of NTFP plants during the
summer months, if necessary. A typical design of such watershed area with
NTFP and other plantations is illustrated below in a diagram.
(Drawing III)
(15)
It will not be appropriate to assume
that all the areas will be identical.
But on one point there are no two opinions is that all
the forest areas should be treated with saturation level watershed
treatment in the form of percolation tanks, CCTs and staggered
trenches from the ridge to valley and the boundary lines well
demarcated by CPTs. The
CCTs and CPTs must be provided with a septa at a regular interval
in order to safeguard any error/omission in laying out the contour
line in case of CCTs, while septa are must in case
of CPTs as the boundary line of the forests is never on the contour
line. The width of septum
should not be less than 1 M which may be increased to 1.5 M in
case of soft sandy soil.
(16)
The Conservators of Forests are requested
to prepare the VSS wise scheme in two parts Part I should contain
saturation level watershed treatment of the area whereas the Part
II should deal with raising of NTFP and other valuable species
with series concept indicating the physical target and financial
requirement. This exercise should be over before 30.09.2002 and
the project proposals from the Conservators of Forests to reach
the Head Office on or before 05.10.2002.
(17)
The scheme thus prepared may form a
part of the Micro-plan. Such schemes need not be confined to the
VSS areas only all the forest blocks should be covered in course
of time.
Sd/- (S.K. DAS) PRINCIPAL CHIEF CONSERVATOR OF FORESTS
To All the Conservators of Forests (Territorial & Wildlife) All the Divisional Forest Officers (Territorial & Wildlife)
/ Copy to all Rang Officers through their Divisional Forest Officers Copy to the All the Additional Principal Chief Conservators
of Forests/Chief Conservators of Forests in Prl.CCFs office. Copy to Circular stock file.
TCBO
SUPERINTENDENT
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