hydroelectric powerplant

1. REQUIREMENT OF HYDRO-METEOROLOGICAL DATA
for
1070 MW Naba Hydro Electric Project
Upper Subansiri District,
Arunachal Pradesh

2. BACKGROUND
 1070 MW Naba Hydroelectric Power Project is located on upper reaches of Subansiri
River near Naba Village, in Upper Subansiri District of Arunachal Pradesh.
 The Memorandum of Agreement (MoA) between Government of Arunachal Pradesh
And M/s Abir Infrastructure Private Limited was signed on 26th April 2011 for
Implementation of the Subansiri basin ranging from EL ±1035m Up to EL ±780 m.
 As Per Terms of MoA M/S Abir Infrastructure Private Limited floated a Special Purpose
Vehicle (SPV) named Naba Power Private Limited for development of Naba HE Project.

3. PROJECT LOCATION
 Naba HE Project is located in upper reaches of Subansiri river near Naba village. The
dam site coordinates are 28o22’ 18.53” N latitude & 93o 35’ 52.63” E longitude and the
powerhouse site coordinates are 28o23’ 30.18” N latitude & 93o 40’ 56.50” E longitude.
 The dam site of this project is located about 42 km upstream of nacho town in upper
Subansiri district of Arunachal Pradesh. Powerhouse site is located on right bank of
Subansiri river near Naba village.
 Powerhouse and dam site can be accessed by all-weather roads connecting Daporijo-
Limeking road running on right bank of the river. Major villages/towns present along
the Daporijo – Limeking road are Taliha, Kodak, Siyum, Aying moring, and Nacho &
Limeking.
 The nearest railhead is located Silapather, Assam. Nearest airport is at Dibrugarh in
assam.

4. PROJECT LOCATION MAP
Naba Project Location

5. PROJECT COMPONENTS
 A Concrete Gravity Dam of 99.19 m height (above foundation level) and 285 m length
at top with FRL at EL.1028 m has been proposed for Naba HEP.
 A Central spillway comprising of 7 Nos. of sluice type and 1 No. of surface type spillway
have been proposed to pass the design flood of 12500 cumecs.
 The design discharge of 465.76 cumecs will be conveyed through one number of
concrete lined 12.0m dia. horseshoe shaped HRT 9669m long and two no. of pressure
shafts (8.5m dia. & 7.0m dia.) further branched to powerhouse with 5 units of vertical
francis turbine of 200 MW each for power generation.
 To utilize the environmental releases, Dam Toe Powerhouse with installed capacity of
55MW + 15MW has been proposed.

6. GENERAL LAYOUT OF NABA HEP

7. HYDROLOGY AND VIEWS OF CWC
 During the PFR stage, the hydrological studies for Naba HEP has been carried out
considering the available discharge data at Chouldawaghat, Gerukamukh and Menga
discharge observations sites for the period 1973-2008.
 Since the discharge data used for water availability studies is up to 2007-08 only, CWC
recommended to use latest discharge data of subsequent years and update the
hydrological studies for the project.

8. CHOULDHAWAGHAT G&D SITE
 CWC has established Chouldhawaghat Gauge Discharge site on Subansiri River which
is a tributary of River Brahmaputra in Lakhimpur District.
 The coordinates of Chouldhawaghat GD site are 94o15’10”E longitude and
27o26’51”N latitude and the hydro-meteorological data collected from
Chouldhawaghat GD site comes under classified data of Brahmaputra Basin
Organization.
 For firming up the hydrological studies and to get the approval of Water Availability
studies from CWC/CEA, the Hydro-Meteorological data of Chouldhawaghat GD site is
required.
 As per Hydro-Meteorological Data Dissemination Policy, 2018 request has been made
to the Chief Engineer, Brahmaputra Basin Organization for release of classified
Chouldhawaghat GD site data.

9. REQUIREMENT OF HYDRO-METEOROLOGICAL DATA OF
CHOULDHAWAGHAT SITE
 Requisition has been made from M/s Greenew Urja Private Limited with ref. to
GUPL/NABA/CWC/BBO/20220706 dated 6th July 2022. NOC for collection of Hydro-
Meteorological data on behalf of Naba Power Pvt. Ltd was also attached.
 General Hydro-Meteorological Data Request Form requesting the Chouldhawaghat site
data from 2002-03 to 2021-22 for monsoon and non-monsoon periods along with
Secrecy Undertaking form has been sent to the Chief Engineer, Brahmaputra Basin
Organization.
 Long term Hydro-Meteorological Data services of CWC Chouldhawaghat GD site will
help in developing reliable hydrological parameters and firming up hydrological studies
for Naba HEP.
 Therefore, it is requested to make available the requisitioned Hydro-meteorological
data of CWC Chouldhawaghat site for finalization of Hydrology studies of Naba HEP
DPR.

10. REQUISITION LETTER M/S GUPL

11. NOC ON BEHALF OF M/S NPPL

12. JUSTIFICATION NOTE

13. SECRECY UNDERTAKING FORM

14. CONCLUSION
 1070 MW Naba HEP Project in Subansiri Basin of Arunachal Pradesh is being
developed by M/s. Naba Power Pvt. Ltd in Joint Sector with Govt. of Arunachal
Pradesh (GoAP).
 For the preparation of DPR and Hydrological Studies for the project, Hydro-
Meteorological Data of CWC Chouldhawaghat site located in Subansiri basin is
needed.
 Details of required data with necessary information duly filled in Justification Note
along with Secrecy Undertaking form has been sent to the Chief Engineer,
Brahmaputra Basin Organization requesting data of Chouldhawaghat site.
 The requested data may kindly be provided for finalization of Hydrological studies for
Naba HEP and to get further approval from CWC/CEA so that this project of national
importance can be taken up.

15. THANK YOU