SITE RECONNAISCANCE NOTES FOR THE PROPOSED KISII STORM WATER DRAINAGE
This forms a report of the reconnaiscance site vist carried out between 27th-29th May 2015 by Zamconsult
Consulting Engineers on the above works whose client is the Kisii County Government. The Consultant’s
Eng. Dr. Zablon Oonge- Team Leader
Eng. Prof. Patts Odira
Eng. Meshack Saboke
Dr. Simon Dulo
Dr. David Siriba
Eng. Simon Onyango
Dr. Isaiah Omosa
The team first met the County’s Director of Environment (Mr. Boke) and one of the officers in his office
(Ms. Violet Kwamboka). It was understood that the Environment Office had undertaken the initial scoping
of the works included in the Terms of Reference.
The team then met the Chief Officer (Mr. Zablon Morioka Ongori) in charge of Lands, Physical Planning,
Housing and Urban Development before meeting the Executive Officer (Mr. Moses Onderi). From this
office it was learnt that the funds for execution of the actual works were allocated by the Central
The following County officers were detailed to accompany the consultant’s team during the inspection
1. Mr. Obuya- Engineer in charge of urban development
2. Ms. Yvonne- Deputy Director, physical planning
3. Mr. Ombaso- works officer
Brief scope of works:
Storm water drainage
Rehabilitation of selected sections of roads
Street lighting at selected locations
A summary of the estimated extent of work and specific locations is captured in table 1
Storm water drainage (km)
Security Lighting (No.)
These estimates were observed to be considerably less than the actual because further dilapidation of the
infrastructure has occurred since the scoping was done. Measurements may have to be done anew.
Walkways not provided, nearly in the entire town
Most drains are open denying or competing for space within the narrow road reserves
Because of steep grades most channel beds are eroded
The capacities of most drains are visually inadequate
Encroachment and hawking on top of drainage system is rampant
Even corrective maintenance appears always delayed
Considerable lengths of road pavements eroded owing to sharp grades. Most damaged are
pavements with only surface dressing as wearing course.
Access culverts should be provided as much as possible by the authorities to avoid unprofessional
construction of the same by affected public.
Implementation of a comprehensive storm water drainage master plan will be the ultimate
Extend drainage by about 50m to start at the upper junction.
The 600 diameter Access Precast Concrete Culvert to RAM hospital is blocked. The culvert capacity
is exceeded as evidenced by the waterline in the upstream drain.
Foul drainage manhole constructed in the drain is obstructing free flow of water. The manhole
should be relocated.
Water pipe crossing just after the gate to RAM hospital is obstructing free flow of water, the
vertical alignment of the pipe should be changed by taking the pipe down in a sleeve.
At the corner, there needs to be a speed bump to channel storm water into the drain on the right.
The road is narrow and congested by NMT and motorcyclists and thus obstructs free flow of
motorized traffic. The consultants and Client representatives agreed on an intervention that will
get pedestrians and motorcyclists off the road.
walkway Cycle track
Rectangular culvert with
slotted precast concrete
Road Right of Way
At the end of police road at the entrance to RAM mortuary there is need for a box culvert with a
drop inlet inspection chamber.
There is a sewer passing at the position of the drop inlet inspection chamber
After the road crossing box culvert, the outfall to the stream needs to be opened, widened and
lined for about 30m.
Just before the stream, there is need for a trash rack to capture solid waste especially polythene
bags which now end up in the stream.
At the stream, a large box culvert is required with a flume entrance.
Plate 1-1: Blocked Access culvert to RAM hospital
Plate 1-2: Sewer manhole in the drain
Plate 1-3: Water pipe obstructing drainage
Plate 1-4: Sewer manhole and pipe at inlet to cross culvert
Plate 1-5: Outfall drain to stream shallow and not lined
Extend the drain up the road raise the kerbs. Terminate the drain in front of Jogoo Lab Services.
The cross culvert at junction to Mayfair Hotel is silted and blocked due to water pipe crossing at
the outlet which holds polythene debris, it should be cleaned.
Access culverts to two premises near Saima village inn are required. The culverts should be
minimum 900mm diameter because the cross culvert up the drain is already 900mm diameter.
Saima Village Inn should be instructed from the County Engineers’ office to construct a grated cut
off drain and channel the storm flow from their compound into the existing drain at their cost.
Between Saima Village Inn and the Prisons gate, the channel needs lining in some areas.
There should be a grated cut-off drain for all the storm water from within the prisons compound
at the prisons gate and this should be channeled to the inlet chamber of the 900mm diameter
The cross culvert referenced above should be unblocked and another line of 900mm diameter
On the opposite side of the road around the bend, kerbs, channels and mitre drains should be
introduced for a distance of about 200m.
There is scouring in the drain near the outlet of the cross culvert which needs improvement.
Between the prisons gate and the stream, there is a sewer manhole in the drain which is
obstructing free flow of water.
Plate 2-1: Inlet to cross culvert at junction to Mayfair Inn
scoured and blocked
Plate 2-2: Saima Village Inn entrance needs grated cut off
Plate 2-3: Cross culvert near Prisons gate blocked.
Plate 2-4: Road shoulders between Mayfair Inn and Stream
Plate 2-5: Outlet of cross culvert near prisons massively
Plate 2-6: Sewer manhole in the drain between Prisons and
ROAD NO. 2 JOGOO AREA: TIMOKA JUNCTION TO DARAJA MOJA STREAM
The 900mm diameter culvert is blocked needs cleaning
The drain is silted and shallow, the capacity should be improved by building a lined drain
There is no space on the road for cyclists and pedestrians, there is need to tarmac 2m shoulder to
drain to open it up for NMT. This will require construction of kerbs, channel blocks and mitre
drains to channel storm flow.
The access culvert in front of car wash is 600mm diameter, smaller than the one up. This should
be replaced with a 900mm diameter culvert
Several enterprises have sprung up on the road reserve over the drain, including two car wash
premises. The premises have blocked the drainage system and reduced the capacity for free flow.
Either the premises should be removed or a bigger capacity rectangular drain constructed with
slotted cover slabs.
Plate 3-1: The 900mm diameter Access culvert is silted
Plate 3-2: The ditch is over-silted and therefore shallow,
Plate 3-3: Several business premises set up over drains
Plate 3-4: Drain completely blocked here
Plate 3-5: This is all that is left for an inlet to a culvert
Plate 3-6: Firewood yard and carwash all on top of the
ROAD NO. 1 CBD: COUNTY COMMISSIONER’S OFFICE ON THE LEFT ALONG MOI AVENUE TO
STADIUM TO NYANCHWA STREAM
The drain is lined in many areas, however some segment still require lining
An outlet headwall is necessary for a culvert joining the drain at the corner off Moi Road
There are twin 600mm diameter culverts which are much silted.
The road is narrow and there is no space for NMT. A covered drain is necessary especially along
Moi road and along Nyanchwa Road adjacent to the Stadium.
The drain is silted and it is evident by water marks on the road that the storm flows on to the road
The outfall to the river is not lined and is overgrown with shrubs which impede free flow of water.
The outfall is on a steep slope, a cascaded drain is required to help reduce water velocity and
erosion at river bed.
At Nyanchwa Stream, there is need for cascaded gabion boxes to reduce erosive effects of the
water as it falls more than six meters.
Nyanchwa stream crosses the road in a one 900mm PCC, which is under size for the amount of
discharge in the stream. This has been evidenced by water filling up the stream and flowing over
the road. A box culvert is necessary which will also be extended for pedestrian crossing.
Plate 4-1: The drain capacity near County Commissioner’s
Office should be improved
Plate 4-2: Several places have improvised accesses to
Plate 4-3: A collapsed inspection chamber
Plate 4-4: Signs of storm water flowing across on top of road
Plate 4-5: Drainage ditch silted and capacity reduced
Plate 4-6: Drainage outfall overgrown with shrubs
Plate 4-7: Drainage outfall is shallow and overgrown with
Plate 4-8: Signs of the outfall being insufficient can be seen on
Plate 4-9: Nyanchwa stream crossing is dangerous for
pedestrians as there is no pedestrian walkway across
Plate 4-10: Nyanchwa Stream had burst its banks the previous
night and flooded homes near the riparian
Plate 4-11: The single line of 900mm diameter PCC whose
capacity is exceeded
Plate 4-12: Signs of water flooding across the road the
ROAD NO. 4, NYANCHWA AREA: NYANCHWA ADVENTIST-BRITHEM ACADEMY
The road from Nyanchwa Adventist through Njugunas to the Kisii-Suneka Bypass junction is in a
poor state and should be constructed and upgraded to bitumen standards with lined drain on
There is also need for new street lighting.
ROAD NO. 6 NYANCHWA AREA: MWANYAGETINGE MARKET ALONG THE SUNEKA BYPASS AND
CROSSING TO NUBIA ROAD
Constructed drains are largely nonexistent in this area hence a lot of erosion due to the large
amounts of water and the steep grades.
Lined drains are required on both sides with scour checks
Access culverts are required to each developed property
There is a lot of ground water flowing from springs into the roads.
There are two short estate roads that should be constructed to bitumen standards and with
covered drains on both sides and street lighting.
There is need for a large cut-off drain on the left of this road, that is the upper side, to collect all
the water from the Njugunas area and outfaal it two ways, one back towards the Nyanchwa
Springs but the major one will outfall along the Nubia village road to Soko Mjinga.
The Nubia village roads are three Number and they should all be upgraded to bitumen standards
with covered drains as they are a densely populated area
The junction at Sokomjinga which was already tarmacked has been completely washed away and
there is a large and deep pool of water there.
There should be a large box culvert and a proper outfall to the river.
ROAD NUMBER 5 NYANCHWA AREA: BRITHERM ACADEMY SCHOOL, KAG CHURCH-NHC FLATS
LINK TO SOKO MJINGA
This road should be upgraded to bitumen standards with covered drains as it is a densely
Plate 9-1: A drain in the Nubia Village
Plate 9-2: A drain in front of Masjid Rahman in Nubia Village
Plate 9-3This road will need to be constructed and
with drains both sides
Plate 9-4: The sokomjinga junction receives storm water from
a large catchment up Nyanchwa hill
Plate 9-5: The junction at Sokomjinga completely
Plate 9-6: The outfall for all the storm at Sokomjinga
Plate 9-7: Sokomjinga near Township Chief's Camp
Plate 9-8: Proposed outfall road to the stream from
Plate 9-9: Link road from Kisii Suneka Bypass
through Nubia Village to Sokomjinga
Plate 9-10: Britherm Academy-NHC flats to Sokomjinga Road
Lower reaches of the road are drained both sides though drain has broken down in some sections
due to steep grade leading to erosion. Upper reaches are not drained. The highest point draining
towards the kilgoris road is at Gekomu primary.
Do a lined open drain on both sides
Section after Christamariane hospital going up is not drained. Lower sections that are drained
drains are not lined.
Both sides of the road will require lined drain with kerbs and mitre drains.
Introduce a paved pedestrian walkway
This section is already done according to the client’s officials
15 ROAD NO 6 MWEMBE AREA: GREEN LIGHTS- FORT JESUS FLATS (NO.6)
This section is already done according to the client’s officials.
Plate 15-1: Menyekwa Market, improvised accesses to business
Plate 15-2: Motocycles on the Kisii Kilgoris road at
Plate 15-3: A culvert completely blocked at Menyekwa Junction
Plate 15-4: A cullvert blocked at gate to Kisii University
16 ROAD NO. 2 AND 3 CBD: POST OFFICE ON BOTH SIDES TO TABAKA OLD STAGE
A new covered drain will be necessary on the right side
The left side should be covered drain all the way from Rangi Mbili to allow on street parking
On the left from opposite Shell there is no drain, a new covered drain will be necessary
On the right there is a covered drain whose capacity will be checked.
On the right, just past Shell, the covered drain is completely silted and blocked.
The collection chamber on the right is over silted.
There needs to be a new cross culvert at Falcon to Channel storm flow into outfall drain
The outfall drain is massively eroded, should be lined and capacity increased.
17 ROAD NO. 5 CBD: FALCON TO DARAJA MBILI
On the right, there is a drain which is lined in some areas and of irregular shape, in some places
wide and in some places narrow.
There is no drain on the left, this is necessary
The outfall drain on the left need to be realigned and storm drainage inspection chambers reconstructed. There is one such inspection chamber under the garage which does not have an
inspection manhole cover hence permanently covered.
The outfall drain should be cleared of all juakali sheds erected on top of it.
The outfall into the river should be a cascaded channel do break the velocity of the water, which
has massively eroded and almost swept away the trunk sewer manhole and line.
The trunk sewer is broken at that point and should be repaired.
Another drain should start just after the outfall near the garage, which will itself outfall just before
the Magnate Billboard
18 ROAD NO. 1 NYANCHWA AREA: SOKO MJINGA-DARAJA MBILI
This road is from Soko Mjinga to Daraja Mbili. The street is very busy with the Daraja Mbili market
operating on Thursdays. Because of this, the drains have been covered by timber planks to create
areas for displaying wares.
The drains on this road will have to be covered on both sides, and the road surface which is already
worn out improved.
There are three Street flood lighting masts on the lower reaches but should be extended to Soko
The drain is in good condition but should be covered around the gate to Kisii level 5 Hospital
It is a high density pedestrian area and a walkway should be done on the right.
The cross culvert from Right to left and the corner after MTC is blocked, and the capacity is small,
being a 600mm diameter.
A new inlet chamber and cross culvert is necessary.
20 ROAD NO. 11 CBD: KISII PARISH CHURCH-BUS PARK TO RAM HOSPITAL-POLICE LINK-STREAM
There is a small covered drain in front of the Parish Church but the slots between the cover slabs
are blocked so the storm water cannot enter the drain. The capacity should be improved.
Covered drain on both sides with separate pedestrian walkway and cycle track is necessary
Just after the lower Junction, motor cyclists requested for an off road parking, because currently
they park on the road.
A new drain is necessary on the right side and the road should be super elevated to drain water
on one side, the left side.
Both the drains should be covered with separate Pedestrian walkways and cycle tracks.
The road is completely washed off because of storm water flow on the road surface, a new base
and surfacing will be necessary.
There should be a covered cascaded outfall because it is a footpath leading to a footbridge.
All the roads must be covered with separate pedestrian walkways
The entrance to the bus park will require a grated channel
23 ROAD NO. 8 CBD: NATIONAL BANK-SAKAWA BUILDING- FALCON PETROL STATION
The road cross falls to the left.
The outfall is through a busy back alley behind the municipal market to Moi Avenue
The outfall is completely blocked and business premises erected on the way leave
From Sakawa Building towards Falcon, there needs to be a covered drain with the earliest possible
outfall on to Moi Avenue
24 ROAD NO 7 CBD: NATIONAL BANK TO POLICE LINK
The road surface is new, but the cross-fall is to the left while the drain is to the right, hence the
drain is of little use.
There should be shallow IBDs on the left from around KCB, with several outfalls on every possible
alley to Moi Avenue.
From Mwalimu Hotel to the Junction to Rehema Academy is a new road, but stone pitching should
be added on cut surfaces as they are high and susceptible to erosion.
From the junction to Rehema Academy to the Gate of the Academy, the construction of the road
and drain is in progress, hence no new intervention is necessary
Figure 25-1: Road No. 2 on the left, the drain should be
improved and covered
Figure 25-2: Road No. 2 left, the Drain should be covered
Figure 25-3: Road No. 2 left, allow on street angle
Figure 25-4: Outfall for Road No. 2, completely blocked
and sides eroded
Figure 25-5: Outfall for road No. 2
Figure 25-6: Inlet chamber for cross culvert leading to
outfall above completely blocked
Figure 25-7: Outfall of Road number 2 with debris
Figure 25-9: Juakali sheds erected on top of outfall to
drain on road no. 5 above
Figure 25-11: The steep fall to the river, see the exposed
trunk sewer manhole and pipe
Figure 25-8: Closer view of outfall above showing
Figure 25-10: Eroded outfall to road no. 5
Figure 25-12: Closer view of the exposed sewer manhole
and pipe already broken
Figure 25-13: Daraja Mbili Drain covered with timber
planks to allow display of trade wares, on right down
Figure 25-14: Daraja Mbili drain on left down
Figure 25-15: Storm water crossing the croncrete block
paved road on the surface after MTC
Figure 25-16: Cross culvert just after MTC is blocked
Figure 25-17: Small capacity culvert on road No. 11
Figure 25-18: No drain at all on their side of road No. 12
Figure 25-19: Road No. 12 completely worn out
because of surface storm flow
Figure 25-20: Cross culvert across the Bypass road is silted
Figure 25-21: This outfall drain leads to a footbridge
over the stream, should be covered cascaded drain
Figure 25-22: Near Level 5 Mortuary a contractor has
blocked the drain
Figure 25-23: Outfall of road number 8 is through a
busy alley so there is no outfall at all as it is blocked
Figure 25-24: Road Number 20 is currently under