Himachal Pradesh has received 917.3 mm rainfall during South West Monsoon 2018. The amount is 11 percent higher than normal rainfall category of 825.3 mm. However at district level there is considerable variation in the distribution of rainfall. Out of 12 districts in the state, rainfall departure has been in deficit in three districts namely Chamba, Kinnaur and Lahul & Spiti by 38 percent, 32 percent and 43 per cent respectively. All these three districts are in upper part of Himalaya, the origin of many rivers & where mountains are mostly snow covered.
Himachal Pradesh Monsoon 2018: District Wise Rainfall Departure Period:01-06-2018 To 30-09-2018 (Source: IMD)
|7||Lahul & Spiti||263.4||458.2||-43%|
On the other hand, seven districts in state have received excess (20% above normal) rainfall. Una, Kullu and Bilaspur are the top three districts which have received surplus rainfall by 59, 49 and 38 per cent respectively. Solan district has received 11 percent above normal level of 1110.8 mm, whereas Sirmour has received almost normal rainfall.
More abnormal rainfall pattern emerges when one looks at the weekly rainfall departure data. For example, in Chamba, rainfall was highly deficit or deficit for 11 weeks in a row. Similarly for 9 weeks continuously, Lahul & Spiti district received deficit rainfall. Kinnaur is the third district where rainfall departure was in deficit for 6 weeks in a row followed by Solan where rainfall departure was in minus continuously for five weeks. In all these cases, the rain-fed crops, the dominant situation here, would have suffered badly.
The data also suggests that Bilaspur and Una are the districts drenched consistently by monsoonal rains throughout the season.
Cloudburst Events in Himachal Pradesh in Monsoon Season 2018
Before and during monsoon season, there were several cloud burst incidents in the State. First on April 7, 2018 there was flash flood[i] in Shimla following a cloudburst event. As per reports, many houses were flooded and cattle swept away in the incident.
On June 5, 2018 a cloudburst incident in Lahaul badly affected[ii] the Leh-Manali highway. The tourists and commuters faced severe difficulty as vehicles faced nature’s fury. Then around June 12, 2018, several tourists stranded[iii] on Manali-Leh highway in Lahaul-Spiti following cloudburst.
On June 13, 2018, eight cattle were washed away[iv] in a cloudburst, following heavy torrential rain in Auraphati village of Chamba district. As per report, a local watermill was also washed apart from huge damages to local water sources.
There was a cloudburst incident[v] reported in Anjani Mahadev area, Mandi on July 2, 2018. The debris swept by gushing water amid heavy rains accumulated in the Anjani nullah. The incident also damaged water supply and foot bridge in the area.
Cloudburst[viii] incidents were reported from three areas in Pangi and Udaipur areas of Chamba and Lahul Spiti districts apart from landslides events from other parts of state. Roads, drinking water pipelines and homes were damaged.
According to reports, there was increase in cloudburst events. State govt also reported of losses to the tune of Rs 120 crores due to cloud burst, flash floods and landslides.
The worst cloudburst events occurred[ix] in the month of August 2018. First incident was report in Karpat nullah in Miyar valley of Lahaul on August 3, 2018 causing flooding[x] in a rivulet in Losar village that disrupted traffic movement on Manali-Kaza road.
Then on August 6, 2018, large tract of agriculture land was reportedly washed away[xi] after cloudburst near Sichling village in tribal district Lahaul Spiti. The flood water entered into houses and standing crop was damaged.
Sources said a chunk of Shimla-Kaza road was also washed away in the flood[xii] and traffic to many villages of the valley, including headquarter Kaza, came to a halt. Similarly, in Kullu district flash flood was reported in Manikaran valley in Jagrai nullah, which washed away a foot bridge at Pulga village.
In the second week of August, there was incessant rainfall across the state causing flash flood and landslides at many locations.
16 people were killed in separate incidences of landslides and flash floods in Solan, Mandi, Hamirpur and Una districs. Shimla reportedly received highest rainfall of 117 years. Traffic on six national highways was affected as landslides blocked the roads; 353 roads were blocked and 923 other state roads were partially damaged.
It seems twelve cattle were swept away in flood[xiv] waters near Bajuara in Kullu district following cloudburst. A few houses were also damaged. The district administration rushed to the spot but it was too late.
Flash Floods, Land Slides , Reservoir Operations
Apart from cloud burst events, there were many flash flood, landslide events during the monsoon in the state particularly in the month of August and September.
Then, on July 27, 2018 torrential rain[xviii] caused flooding in Bhram Ganga, a tributary of Parbati river in Manikaran. The river was in spate and damaged a footbridge, disconnecting several villages. Rains caused damage to a house and a water mill in Chamba districts of Salooni.
On August 18, 2018, flash floods[xix] due to heavy rain in Kullu and Rampur damaged as many as six foot bridges and washed away nine water mills. Flash floods also damaged roads and houses in Chalol and Rasol villages in Kullu district’s Manikaran. Due to heavy rains in Dhundhi, 25 km uphill the tourist town of Manali, roads were damaged.
Continuous rains damaged[xx] public and private property worth crores in Kangra and Chamba districts on August 24, 2018. At least a dozen houses, several shops and cow shelters were damaged across the Kangra district.
Traffic on the Chandigarh-Manali national highway has been blocked following a massive landslide[xxi] along the Beas river on August 25, 2018. Nearly 100 metres of the national highway was badly damaged in the landslide that occurred near Aut in Mandi district on August 24, 2018.
About five people were washed away as heavy rains[xxii] triggered flash floods in Beas river near Manali and Parbati River in Manikaran on September 23, 2018. Two more person died in separate flash flood incidents in the state. Several houses were also swept away in flash floods as the Beas was flowing at a dangerous level. Schools in most districts of the state remained closed.
People residing in low-lying areas, especially in Kangra, Chamba, Kullu and Mandi districts, were evacuated following flood spell in many rivers. Water was released from Pandhoh dam and the Bhakra Beas Management Board (BBMB) also issued flood warning following water release from the Pong Dam due to high inflows.
Till first week of August, water in Bhakra and Pong reservoirs were at lowest level[xxiii] since 1997 and an emergency meeting was called by BBMB with principle secretaries of partner states asking partner states to conserve and utilise monsoon water to the maximum possible extent. By that time, monsoon rain were 11 percent deficient in Sutlej and Beas catchments.
However on August 13, 2018, BBMB had to release[xxiv] water from Pandoh Dam in view of the alarming situation of the silt in the reservoir as heavy rain had caused huge inflow in Beas River. Before this, on August 8, 2018 the rise in Satluj river level damaged[xxv] a local market place at Pavari.
But in the last week of Sept. there was heavy rainfall[xxvi] and floods across the state, following which Gates of dams opened the gates of almost all the dams and reservoirs in various hydro-power projects in the state were opened[xxvii] as they inched close to the danger level.
With there being no let-up in the incessant rains, gates of most dams – Chamera –I, II, III, Baira Siul, Kol, Nangal, Baspa, Shongtong and Larji were opened for flushing. The highest discharge of 11,729.76 cusecs was from Karcham hydro-project followed by 10306.93 cusecs from Shongtong project, both in the Kinnuar in the Satluj basin.
Locals residing in the downstream areas were warned against venturing close to the riverside. The water level in the Pong Dam on Sept. 24 touched 1,385.55 feet, close to the danger mark of 1,390 feet.
The phenomena of extreme events — a new normal situation where some places in the state had received more than 2,000 per cent more rainfall than normal — was a worrisome development.
Dam Floods Himachal 2018
On July 28, 2018, water was suddenly released[xxviii] from the 243 Mw Kashang hydel power project in Kinnuar causing immense damage to apple orchards and pine forests in the tribal district. It is alleged that the water was released without warning. Residents of the affected Pangi village in Kinnaur submitted a memorandum to the district authorities demanding immediate action against the erring officials. Water was first released by the Karcham Wangtoo hydro plant in Kinnaur later the Nathpa Jhakri hydroelectric station also released water from its dam in Nathpa.
Following the incident, the state disaster management authority issued a notice to the management of Kashang hydel project seeking clarification over the release of water without warning. Four years back, state govt had issued guidelines to all the power projects directing them to install alarm and warning system for safety of people during the sudden release of water. The directions were issued after 24 students were washed away in Beas river, after water was released without warning from the Larji dam in Kullu.
Meanwhile, water release from the dams led to an increase in the water-level in Sutlej river which has disrupted power generation operations. The 1500 Mw Nathpa Jhakri, 412 Mw Rampur, 120 Mw Sanjay project and 300 Mw Baspa project were shut down on July 28 due to increased silt levels in Satluj and its tributaries.
Composed & compiled by Bhim Singh Rawat (email@example.com)
Excerpts from Endangered Himalaya, E-Newsletter: 1st-15th August, 2018
-This monsoon entire state was in the grip of torrential rains and resultant floods (amidst rainfall deficiency in many areas). There were many incidents of property damage & people swept away by sudden releases of water in areas around dams and hydro projects.
– For example on 6th August, four shops in Powari market, Rekong Peo, were damaged by mudslide as the diversion tunnel constructed to divert Satluj under the Shongtong Karchham HEP (450 MW), a project under construction, had been eroding the market area. A similar ‘mishap’ occurred on the evening of 27th July, when the residents of Pangi village, Kinnaur found their apple orchards and pine trees destroyed by the sudden release of water from Stage 1 Kashang Hydel Power project (65 MW) without warning.
Excerpts from Endangered Himalaya, E-Newsletter: 15th-30th September, 2018
– Just before the departure a severe bout of showers left many stranded in far flung areas of the state. As per CM statement, the state has suffered from losses amounting to 1500 crores this season due to damage to property and life as a result of 33 incidents of ‘cloudbursts’ and 391 landslides.
Flash Floods Affecting Hydro Power Projects and Power Generation
Due to heavy rainfall and flash floods, silt level in the Sutlej River also increased disrupting[i] power generation operations from four power projects and triggered blackout in parts of Himachal and in industrial corridor.
There was a sudden flash flood[ii] in the Sutlej River on August 8, 2018 damaging shops and houses in Ribba and Powari area of Kinnaur. An under construction power project was also damaged and power generation came to a halt due to increase siltation[iii] in Sutlej river.
In a contrary situation, power generation at Mukerian hydel project and Pong dam at Talwara on Beas River stopped due to non-release of water from Pong dam. Nearly 20 power generation machines, which together generate 621 MW (6.21 lakh units per hour), were closed since August 5, 2018.
On August 13, 2018, a flood warning was issued for tourists and people residing in low-lying areas following water release in Beas River from the Pandoh Dam.
Then in the last week of September 2018, the gates of almost all the dams[iv] and reservoirs (Chamera –I, II, III, Baira Siul, Kol, Nangal, Baspa, Shongtong and Larji) in the state were opened as they almost inched close to the danger level following heavy rainfall.
The Bhakrha Beas Management Board (BBMB) dam authorities also released 49,000 cusecs water from Pong dam in the Beas river. Similarly, 1 lakh cusecs was released in the Sutlej river from the Ropar Barrage on September 24, 2018 night.