Kigali Sub Area Plans S
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o z a r c h i t e c t u r e . e r a . e d a w. t e t r a t e c h . w i n s t o n a s s o c i a t e s JUNE 2010
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K IM I H URURA
VISION AND PROGRAMMING ..................................1 Vision .....................................................................3 Development Program .........................................5 SITE PLAN ..................................................................6 Framework Diagram .............................................6 Illustrative Site Plan...............................................7 Open Space/Greenway Zone .............................10 INFRASTRUCTURE....................................................14 Transportation .....................................................14 Drainage ..............................................................20 Water ...................................................................24 Sanitary Sewer ....................................................26 Power/Dry Utilities ..............................................28 DEVELOPMENT & DESIGN GUIDELINES ...............30 Design Guidelines ...............................................30 Mixed Use Commercial Zone .............................30 Medium and Low Density Hotel Zones ..............32 Kimihurura Residential Zones .............................34 Architectural Standards ......................................34 MUNICIPAL FINANCING .........................................36 Phasing Plan ........................................................36 Municipal Financing ............................................37
FIGURE 1: THE KIMIHURURA ROUNDABOUT serves as a symbol of the new Rwanda and inspiration for the future.
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The Kimihurura Sub Area is centrally located within one of the most highly developed areas of Kigali and is surrounded by important existing and proposed urban elements. These include Government of Rwanda Ministries, Parliament and Agencies. In addition, the new Kigali Conference Center and Hotel, located adjacent to the Sub Area site, will anchor Kimihurura development and position it as an iconic Kigali location. The Sub Area is envisioned to be a Gateway to the City from the Kigali International Airport and an extremely important symbolic urban space for the “new Rwanda.”
K IM I M IHU IHURURA
FIGURE 2: THE KIMIHURURA SUB AREA is located centrally in Kigali, to the east of Nyarugenge and to the west of the Kigali International Airport.
KI G A L I S U B A RE A P L A N N I N G
VISION Gateway Experience. In its position due west of the Kigali International Airport, the Kimihurura Sub Area will provide a Gateway experience for arrival to Kigali. Coming from the Airport, the visitor arrives first at the new Convention Center and Hotel complex, which will be a major Kigali landmark with its Rwandan inspired dome. Next, the Kimihurura Roundabout directs the visitor to the Kimihurura Sub Area site, which welcomes the visitor into a dense, vibrant, and animated mixeduse commercial center. The site is more than a gateway though: by design, it easily welcomes local Kigali residents, who are drawn to the site from the north (Kacyiru hill and the rapidly growing areas of Nyarutarama and Kinyinya), the west (the new CBD in Nyarugenge) and the south (the populous Kicukiro area). The Kimihurura Roundabout symbolizes this diverse access and the celebration of Kimihurura Sub Area for all Kigali citizens. Symbol of the Future. In addition to its role as Gateway, City leaders and stakeholders would like the Kimihurura Sub Area to become a symbol of the “new Rwanda”, and evidence that Kigali is a planned and well organized city. The Mayor envisions iconic high-rise buildings tapering down to the ground, situated in a beautiful green garden setting, providing an elegant transition into the older parts of the City. These elements symbolize Rwanda’s rebirth and its commitment to a globalized and sustainable future.
FIGURE 3: THE NEW KIGALI CONVENTION CENTER at Kimihurura has already started construction. It will form a key element for the future program of the Sub Area that will be elaborated by the development program shown in this report.
Build on Important Existing Elements. The Kimihurura site area has already been acknowledged as an important location by virtue of new government facilities (such as the Ministries of Revenue, Defense, office of the Prime Minister, and others), commercial development such as the KBC, and public beautification projects such as the Kimihurura Roundabout, located in the vicinity. The high level governmental uses should shape programmatic decisions for the site, providing space and access for organizations and visitors conducting business with them, while at the same time protecting their privacy and security. In general, stakeholders would like to ensure linkages between the Sub Area and surrounding businesses and neighborhoods so that commercial, retail, entertainment and recreational facilities can be accessed by all.
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Strong urban parks and green identity already exist and shall serve as key design element. The three major public green spaces located at the site (the Kimihurura Roundabout, the Circular Park located next to the ministries, and the large green area located at the southern end of the site) are important anchors that will shape the design. A large portion of the site currently occupied has large open spaces with ancient trees that shall be protected and preserved. Stakeholders would like the Roundabout and gardens to be strengthened and utilized as urban backdrop to restaurants and other urban pedestrian uses surrounding it. They envisioned new development to frame the Roundabout. At the same time, there were traffic concerns at the roundabout, with the desire for separated pedestrian/auto network management, such as a pedestrian bridge or alternative road network that would separate local and/or pedestrian traffic from regional traffic.
FIGURE 4: THE KIGALI BUSINESS CENTER (KBC), located at the Kimihurura Roundabout, was one of the first private sector developments.
FIGURE 5: ADJACENT TO THE KIMIHURURA SUB AREA, there are several key Rwanda ministries, such as the Departments of Revenue, Defense, Foreign Affairs and the Prime Minister’s Office. The circular park adjacent to them should provide passive relaxation to employees and serve as a transitional zone from the higher activity areas of the new Sub Area.
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Developer stakeholders were interested in higher density programming, but they also valued environmental concerns, such as greenways and landscaping, management of the wetlands, and use of native plants or bamboo instead of eucalyptus. Some stakeholders desired small gardens and felt that agriculture in the urban area is good. They felt that the natural forested area should be protected and become a design element, especially for the Hotel area. They thought that greenbelt linkages to surrounding areas should become defining design element throughout site, emphasizing pedestrian/greenways and connections into surrounding areas. They also wanted to strengthen the pedestrian connection between Roundabout and Government Center. Gasabo Mayor Claudine Nyanawagaga highlighted public leisure space and attention to the youth population. Previous Design Work for the Sub Area. The Kigali Conceptual Master Plan addressed the Kimihurura (Kacyiru) Round-about as a model case study for commercial redevelopment. It recommended further growth there to build upon existing retail use, increase density, extend green belts and create a streetscape with bridge and underpass connections for pedestrian activity. Peter Rich Architects further developed the concept to create a strong pedestrian promenade connection between the Kimihurura Round-about and the government circle drive. Taller mixed use buildings were introduced in a radial pattern from the Roundabout, preserving views, as well as a hotel and high density residential use zone at the military reserve site, which preserved existing tree lines. These elements of Rich’s scheme and the location of parking below buildings have been developed in the Kimihurura Sub Area Plan.
FIGURE 6: THE EXISTING CIRCULAR GOVERNMENT PARK adjacent to the Kimihurura Sub Area on the west is already beautifully landscaped. It should be further enhanced to serve as one of three major parks that will be part of the Open Space/ Greenway network.
FIGURE 7: THE EXISTING KIMIHURURA SITE has beautiful forests and stands of ancient trees that should be integrated into the plan, protected and preserved.
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KIMIH U RU RA KI G A L I S U B A RE A P L A N N I N G
DE V E LOPMEN T PROG R AM Based on Kigali and Gasabo District leadership guidance, stakeholder visioning, and environmental and socio-economic analysis, a development program was produced as a basis for the Site Plan. Kimihurura Development Program shows the space allocation to the different uses. This program ultimately formed the basis of the Site Plan which includes a Framework Diagram, highlighting the various development zones; and the Illustrative Site Plan, which demonstrates one possible urban design outcome.
TABLE 1: KIMIHURURA DEVELOPMENT PROGRAM ITEM
Number
Unit
of Units
Type
Population
MIXED USE HIGH DENSITY OFFICE/RETAIL/RESIDENTIAL Retail
45,000
SM
Office
180,000
SM
120
Dwelling Units
1,300
Rooms
Residential*
360
HOTEL ROOMS Hotel-Medium Density Hotel-Low Density
200
Rooms
1,500
Rooms
Residential (Med.- High Density ~140 DU/Ha)
434
Dwelling Units
1,300
Residential (Med.- Low Density ~70 DU/Ha)
286
Dwelling Units
860
720
Dwelling Units
200-300**
Students
Total RESIDENTIAL
Total Elementary School
2,520 *Flexible: can be expanded or reduced per market drivers. **Lower proportion of students in Kimihurura Sub Area population.
FIGURE 8: KIMIHURURA ROUNDABOUT. As one of the first public beautification projects in Kigali, the Kimihurura Roundabout holds iconic status, acting as the site of many weddings and celebrations near the central woman and child statue.
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SI TE P LAN In this section of the report, the Vision and Programming are applied to the development of a Site Plan, comprising a Framework Diagram and an Illustrative Site Plan. The Framework Diagram shows the various development zones, guidelines for which are detailed in the later section titled Development Guidelines.
F RA MEWORK DIAGRAM The Kimihurura Framework Diagram (Figure 9), shows the following uses in the Sub Area: • Open Space/Greenway Zone • Mixed Use High Density Commercial/Retail/Office • Medium High Density Residential • Medium Low Density Residential • Medium Density Hotel • Low Density Hotel • Primary School
TABLE 2: KIMIHURURA SUB AREA LAND USE
MIXED-USE ZONES High Density
LAND USE
AREA (ha)
% of SITE
Medium Density Neighborhood Center RESIDENTIAL ZONES High Density
OPEN SPACE
21.69
24.5%
MIXED USE - HIGH DENSITY
15.50
17.5%
PLAZA PROMENADE
1.08
1.2%
RESIDENTIAL -MED.-LOW DENSITY (~70 DU/Ha)
2.46
2.8%
RESIDENTIAL-MED.-HIGH DENSITY (~140 DU/Ha)
4.12
4.6%
HOTEL - LOW DENSITY
1.66
1.9%
Low Density (Eco-Tourism/Retirement Housing)
HOTEL - MEDIUM DENSITY
6.33
7.1%
CIVIC
EDUCATION
0.42
0.5%
EDUCATIONAL
INFRASTRUCTURE RIGHT-OF-WAY
35.45
40.0%
TOTAL
88.71
100.0%
Medium-High Density Medium-Low Density HOTEL ZONES High Density/Conference Center Medium Density
OPEN SPACE
0 0
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100 400
200
m ft
800
FIGURE 9: THE KIMIHURURA FRAMEWORK DIAGRAM shows the development zones.
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KIMIH U RU RA KI G A L I S U B A RE A P L A N N I N G
I L L U S T RAT I V E S I T E PLA N The Kimihurura Illustrative Site Plan (Figure 10), shows a representation of what future development might look like based on the Framework Plan and Development Guidelines (last section of this chapter). It comprises intensive development that balances and strengthens the existing fabric of the area. The Kimihurura Roundabout is featured in the plan as a celebratory space, reflecting its heritage as a key location in Kigali. The design of the mixed use commercial zone consists of tall iconic modern buildings emanating radially from the Roundabout like a star. These buildings are tied together by a second level circular walkway that provides safe pedestrian access all around the circle. The walkway is lined with shops, restaurants and viewpoints that will excite and entertain the user.
0 0 FIGURE 10: KIMIHURURA ILLUSTRATIVE SITE PLAN
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100 400
200
m ft
800
FIGURE 11: COMMERCIAL CENTER RENDERING. View from north east.
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SI TE P LAN ILLU S TRATIVE SITE PL AN c o nt inued To the west of the Roundabout, a pedestrian promenade draws users to a circular Plaza, anchoring a pedestrian system threading through the mixed-use commercial district. The tall buildings have retail on the ground floor and office/residential above. The promenade sets the stage for a variety of street uses, such as walkways, outdoor restaurant areas, fountains and kiosks, small gardens and public art. It is a place where people can shop, dine, or just enjoy watching the urban street life. Building tower floor plates, of no more than 16m width, allow vistas between buildings, as well as natural light to the street. Farther to the west, the existing circular Ministry Park has an open pavilion with soft green landscaping as a backdrop, providing a peaceful mood that contrasts with the vibrant social hardscape of the urban center. Tall radial mixed-use buildings are also found emanating from the north side of the Roundabout. As a Gateway to Kigali City, Kimihurura highlights the sense of arrival for visitors, but it also supports both local Rwandan and international markets. The new plan consolidates a strong focal point and sense of place for surrounding development, including the nearby Convention Center and Hotel under construction, ministries/government agencies, and residential neighborhoods.
FIGURE 12: THIS VIEW FROM THE TOP OF ONE OF THE RADIAL BUILDINGS LOOKING NORTHEAST shows the circular Shopping Plaza that forms a focal point inside the Kimihurura shopping/restaurant district. The plaza supports both automobile and pedestrian traffic. A covered walkway allows the visitor to circulate comfortably even when it is raining. Restaurants and outdoor gathering spots enliven the plaza to make it a festive and animated space. The top of the drawing features the pedestrian Promenade leading to the Kimihurura Roundabout and the Convention Center beyond.
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GREENWAY WITH NEIGHBORHOOD ACCESS
GREENWAY WITH NEIGHBORHOOD ACCESS RESIDENTIAL NEIGHBORHOODS
HOTEL PARK
FIGURE 13: THE DUAL CIRCULATION PATTERN AT KIMIHURURA, shown above, illustrates the primary circulation routes visitors and city-scale arrivals to the site. The secondary circulation pattern, equally important, provides access from neighborhoods to the north, and surrounding areas.
FIGURE 14: THE RESIDENTIAL NEIGHBORHOODS in the southwest part of the site are geared towards the Rwanda urban dweller as well as the international business/organization community.
FIGURE 15: HOTELS ARE POSITIONED TO LOOK OUT OVER THE NORTH/ SOUTH URBAN PARK, providing access for their guests to walkways that circulate within and through the wooded grove to the Convention Center and commercial areas.
Circulation through the mixed-use zone is sensitive to the complexity of market populations for the site, and to the need for non-automobile alternative forms of access for many people. In addition to the primary access afforded on arterials and the Roundabout, the mixed-use commercial zone is bisected by a circular drive that starts in the neighborhoods on the northwest part of the site, loops down to the Kimihurura Sub Area Residential and Hotel zones, and then loops up to the east of the Convention Center to the surrounding residential neighborhoods on the northeast. This loop provides a second circulation structure that ensures local access to the site. To the south of the mixed-use commercial zone, a strong east west drive connects pedestrians to the Convention Center via a charming pocket park that also links to the greenway.
The Kimihurura Residential neighborhood center includes medium high (100 DU/ Ha) and medium low (70 DU/Ha) areas. Blocks include buildings and parking as well as landscaping in their interior courtyards. Because there is such a high proportion of retail in the mixed-use commercial center, neighborhood community centers and retail would be limited in this zone to groceries, small shops selling necessities, and pharmacies. Likewise, because the market population for this neighborhood is expected to be more short term, transient, or professionally oriented, the interior block landscaping is envisioned to be more low maintenance with urban agriculture with fruit trees and ornamentals rather than subsistence or market gardens. For the same reasons, this area has a lower proportion of school children than more long term established neighborhoods; however, a primary school is located to the southwest to accommodate children from this and surrounding neighborhoods. nd commercial areas.
To the southeast of the mixed-use commercial zone (and due south of the Convention Center) lies the Kimihurura Hotel zone, which includes five Hotel sites for medium density and low density Hotels. Four of these sites are envisioned to accommodate conference and international grade Hotels that will serve the Conference Center and needs of organizations with business in Kimihurura and Kacyiru. Additionally, these Hotels may serve the recreational site to the south of the hotel zone, which may potentially promote sports and other activities that will draw large international crowds.
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SI TE P LAN OP E N SPACE / GREEN WAY ZO N E
0
100
FIGURE 17: A SMALL PUBLIC PARK south of the mixed use commerical zone provides a tranquil respite for the convention, hotel and shopping visitor.
FIGURE 18: THE CIRCULAR GOVERNMENT PARK to the west of the Sub Area links to a semicircular residential park via a “green street�.
FIGURE 19: THE KIMIHURURA HOTELS look out over a forested park with peaceful walkways that provide access to the Convention Center, the Residential area and the Commercial zone.
FIGURE 20: ARRIVING AT KIMIHURURA on the arterial from Nyarugenge, the Ministry of Defense Park sets the stage for the dramatic skyline of Kimihurura.
200 m
0
400
ft
800
FIGURE 16: THE OPEN SPACE/GREENWAY ZONE structures the layout of the whole design, linking it to nature and the larger Kigali greenway system shown in the Kigali Conceptual Master Plan. In Kimihurura, the Open space/Greenway Zone includes the Kimihurura Roundabout, two major circular parks, the linear park in the Hotel zone, a smaller residential park, a small urban park in the mixed-use commercial zone and school play yards. These are all linked in a seamless network by pedestrian/bikeways adjacent to roads through the Sub Area. In addition, the internal Greenway links to the north and south to Kigali wetlands which shall also be preserved as Open Space. Like the road rights-of-way (shown in the Infrastructure section below) the Open Space/ Greenway Zone has been defined by engineered boundaries, and shall be set aside (via easements or purchased land) by the municipal government to preserve this land in perpetuity.
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This view of the Kimihurura Sub Area highlights the beautiful urban landscape that frames the Kimihurura Roundabout and links to the Conference Center.
FIGURE 21: KIMIHURURA SUB AREA VIEWED FROM THE NORTHEAST LOOKING NORTHWEST.
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SI TE P LAN A RRIVALS & T HE V IEW F RO M AFAR As a Gateway to Kigali City, Kimihurura highlights the sense of arrival for visitors, but it also supports both local Rwandan and international markets. The new Plan consolidates a strong focal point and sense of place for surrounding development, including the nearby Convention Center and Hotel under construction, Ministries/ Government Agencies, and Residential neighborhoods.
FIGURE 22: THE KIMIHURURA SUB AREA enhances the sense of arrival for the visitor. Coming from the Kigali International Airport, excitement is generated first by the new Convention Center, then the celebratory Roundabout, and finally by the thrilling urban landscape of the tall structures of the Sub Area.
FIGURE 23: ARRIVING FROM NYARUGENGE, the urban landscape of Kimihurura will be memorable as a statement of the new Rwanda.
FIGURE 24: THE VIEW EAST OF KIMIHURURA’S SKYLINE from the Ministry of Defense Park will be inspiring.
FIGURE 25: ARRIVING FROM THE SOUTH, the visitor will be drawn into the interior circular plaza by curiosity about its liveliness.
FIGURE 26: VIEW FROM THE SOUTH LOOKING OVER THE PROPOSED RECREATION SPORTS FACILITY PARK.
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View of the Kimihurura Sub Area from above the Ministry of Defence and Government Park looking east. It shows the proximity of the Kimihurura Sub Area to the Kigali International Airport, which is located at the very top of this rendering.
FIGURE 27: KIMIHURURA ILLUSTRATIVE SITE PLAN VIEW LOOKING EAST.
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I N FRASTR UCTURE T RA NSPORTATION REGIO NA L C ONT EX T The regional location of the Kimihurura Sub Area in the central area of the City of Kigali, plays an important role in transportation planning. Primary regional destinations include the Nyarugenge Central Business District (CBD) located three kilometers to the west and the Kigali International Airport located six kilometers to the east. See Figure 28: The Regional Location of Kimihurura. The Kimihurura Sub Area is an existing developing urban area with a strong government and military presence. It is being planned as a mixed use Commercial, Retail and Residential neighborhood, with Hotels supporting the new Convention Center as another local attraction. Traffic generation is expected to be typical of a commercial/residential neighborhood with a strong influence from the Convention Center as another main attraction.
TRAVEL MOD ES Multiple modes of transit will be utilized within the Kimihurura City Center Area. The Kinyinya Surbana Transportation Report discusses a typical split of transportation modes where 75% percent of travelers opt for public transportation such as buses, with the remaining 25% utilizing the personal automobile. This split is expected to be similar to other areas, however for different reasons. In Kimihurura, the high public modal split will be due to its urban mixed-use character more than to its socio-economic character. Internal circulation within this City Center is expected to be largely by non-motorized and/or local public/private bus transportation. The utilization of personal vehicles for transportation will be limited in this area for two reasons. A significant amount of the market will be convention related hotel and apartment short-term residency with international tenants, who will tend to use non-personal transportation.
K E Y T R AN S P O RTATIO N GO A L S •
• • • •
Utilize existing transportation corridors and developed areas for new and improved roadways to reduce the impacts on the natural environment within and surrounding Kimihurura. Improve access to or between the Government Circle and proposed Convention Center. Create a better connection between the Residential areas surrounding the City Center and the City Center itself. Promote pedestrian and bicycle safety and access and the use of public transportation to destinations around the City. Establish better generalized bus routes and stronger access to the Central Business District, Airport, as well as creating a stronger link to the south of Kimihurura.
KINYINYA
PREFERRED ROUTE TO CITY CENTER KIGALI CITY CENTER
PREFERRED ROUTE TO AIRPORT KIMIHURURA
KIGALI INTERNATIONAL AIRPORT
In addition, the mixed-use quality of the buildings and neighborhoods will allow for a high ratio of non-personal automobile transit modes, including taxi and moto-taxi, bus (private and public), and bicycle/pedestrian traffic. Motorized transportation bringing people to the site will be through a variety of means. Personal vehicles. This travel mode includes cars and motorcycles used for transit in and around Kimihurura for personal business. The use of personal vehicles is anticipated to be a secondary mode of travel within Kimihurura, based upon its smaller overall size and strong mixed-use design. While some employees and visitors may drive to their respective locations within Kimihurura, most will opt to use public transportation, private hotel transit, bikes, or pedestrian modes of transportation. Public Transit. Public transportation (including taxis, buses, and hotel transit) is expected a significant mode of transit for residents and employees. A mass transit system (bus, shuttle, taxi) currently provides service throughout Kigali City with service in and around Kimihurura. With this service expected to continue, mass transit options will be available to the public wishing to access the Convention Center and other features
REBERO MASAKA FIGURE 28: THE REGIONAL LOCATION OF KIMIHURURA shows its proximity to the Kigali City Center and the Kigali International Airport
of the Kimihurura area. In order to facilitate easy access to buses, there will be bus stop locations at various locations within Kimihurura at major intersections and near major business and government buildings with loops accessing the Convention Center and Ministry Circle sites. Private Transit. Since the Kimihurura site is planned to include Hotels and Residences that will support the Convention Center, private transit modes including vans and small shuttles buses are anticipated to be operated by the hotels. These vehicles will be available to transport guest to
and from the Airport, as well as to other visitor destinations in the region. Bicycles. Bicycles are expected to be used by residents who live in the neighborhoods adjacent to the City Center who are accessing places of employment or other destinations within the area. Bicycles may also be used by hotel guests for leisure and convention access, also linking to the proposed bike ways along the wetland/Parks.
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Pedestrians. Pedestrian access is predicted to be most prevalent by employees who live in the adjacent neighborhoods and also by guests accessing nearby destinations. While all roadway classifications include provisions for pedestrian access, there are also several pedestrian friendly routes throughout the site, including the Park between the Hotels, the urban Promenade through the Mixed-Use Center, and the northwest/southeast running “green street� through the residential zone.
anticipated additional load of traffic that will result from the increase in population. Horizontal Curves. Based on the proposed design speed for each roadway classification, minimum horizontal curvature radii have been provided as indicated in Table 3: Road Design Criteria.
V E RT I C AL AL I G N M E N T DESIGN S PEED As indicated in Table 3: Road Design Criteria, the design speeds proposed for vehicles vary between the road classifications. The highest design speeds are along the major arterial roadways and step down as traffic proceeds into the collectors and local type roadways. The highest design speed is for the arterial roadway which has been proposed to be between 50 and 90 km/hr. This higher design speed is reflective of the faster transit speed expected for vehicles traveling a longer distance to and from outlying areas and into the City Center. The next range of design speeds includes the Collector roadways that step down to the 30-50 km/hr range. These roadways mix motorized transit with a higher concentration of bicycle and pedestrian traffic. Local streets are assumed to have low design speeds under 30 km/hr.
HO RIZO N TA L A LIGNMENT The horizontal alignment of the proposed roadway improvements associated with Kimihurura is indicated on Figure 29: Kimihurura Roadways. Horizontal design criteria is also included in Table 3. Roadway Location. While many of the roadways alignments within Kimihurura represent completely new construction, much of the roadway location is based on the existing roadways currently located within the site along with the existing access to the Government Circle. New roadway locations were determined by their location to the proposed Convention Center, the need to connect the Convention Center to the existing government buildings within Kimihurura, and the
Due to the hilly terrain within and surrounding the Kimihurura area, vertical alignments are a key design element in the roadway design. While roadway profiles have been developed for key roads around the convention center, we have provided basic design criteria to be used for the remaining roadways for the maximum grades for the various roadway classifications as indicated in Table 3. The following are design elements that are recommended as guiding principles, and should be verified further as the design of the project progresses.
TABLE 3: ROAD DESIGN CRITERIA ROAD
CLASSIFICATION
SPEED
HORIZONTAL CURVE
PROFILE GRADE
(km/hr)
MINIMUM RADIUS (m)
MAXIMUM (%)
1
Local
30
30
8
2
Minor Collector
30-50
35
12
3
Major Collector
30-50
35
12
4
Mafor Collector
30-50
35
12
5
Arterial
50-90
100
11
in length in straight roadway segments. These variances can be used to help with keeping the roadways within existing road corridors or to aid in upgrading the existing urban setting roadways to accommodate the increase in vehicular and pedestrian traffic in the area.
Proposed Profiles. The maximum road grades have been developed utilizing lower grade percentages on roadways with a higher design speed due to stopping sight distance considerations. For the residential roadway classifications, higher profile grade percentages can be tolerated due to the lower design speeds. Grades in the areas of public parking and/or heavy pedestrian traffic may need to be revised to provide better parking and pedestrian access where possible. Intersection Transitions. In order to provide safer intersections, flatter grades are recommended at intersections, especially for stop conditions. Intersections should be designed with a maximum 4% grade for ease of stopping and starting vehicles. On the highway and collectors roadway classifications the intersection transitions should extend for a minimum of 30 meters and for residential roadway classifications the transition should extend for 20 meters. Variances. In order to achieve other important design goals within the Kimihurura project, short sections of the roadways could be steeper by 1 or 2% in sections limited to 30-60 meters K I M I H U RU RA - I NFRA STRU C TU RE 5-15
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I N FRASTR UCTURE T RA N S P O RTAT I O N 1445
RO A D WAY C L A SSIFIC AT IO N
SECTION 4A
1450
147 0
5 146
1460
SECTION 3B
1 455 1460 1465 1470 75 14
SECTION 2A PROMENADE
75 14
SECTION 2B, 2C, 2D PROMENADE
SECTION 2B, 2C, 2D PROMENADE
SECTION 1A
1500 SECTION 4B
SECTION 3B
1495
SECTION 1A
90 14
In support of development of Kimihurura, roadway improvements will be required in order to provide for multiple modes of transportation access to and from the Sub Area. The roadway improvements in Kimihurura will include some improvements to existing roadways as well as the majority of new roadway construction. New construction includes arterial and collector roadways with some new local level roads, located within the residential neighborhoods. Existing roadways will be upgraded to fit the criteria for arterial, collectors and local roads. With the addition of the Convention Center, considerable roadway infrastructure will be needed to fit the proposed program. The planned roadway improvements include the following roadway types:
Parking Lanes. Several roadway sections incorporate parallel or diagonal parking to facilitate the need for parking in the designated areas. For parallel parking lanes, a 2.5 meter width has been provided. In some areas, the surface treatment will be typical asphalt pavement, and in other areas pervious pavers shall be used. Six meter wide lanes have been provided for the diagonal parking zones. Bike Lanes. Due to the high level of bike traffic anticipated in this area, most roadway sections include either 2.0 meter or 2.5 meter wide dedicated bike lanes. The bike lanes are typically separated from the vehicular lanes with either a horizontal landscaped planting area or a vertical curb break. The wider roadway sections have combined pathways of varying widths that will be used for both bicycles and pedestrians.
1 485 SECTION 3A GREENWAY
C RO SS S E C TIO N S 14 75
1480
1
1 145
SECTION 1A SECTION 3C SECTION 5
LEGEND ROADWAY SECTION 1: LOCAL ROADWAY SECTION 2: PROMENADE ROADWAY SECTION 3A: GREENWAY ROADWAY SECTION 3B/C: MINOR COLLECTOR ROADWAY SECTION 4: MAJOR COLLECTOR ROADWAY SECTION 5: ARTERIAL
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Carriageway Width (Right of way). The proposed carriageway width varies according to the roadway classifications. Widths range from 13.5 meters for local roads up to 34 meters for the main arterial roadway section. The proposed carriageway is wide enough to include the various vehicular, pedestrian and bike lanes within each cross section. Proposed landscaped medians, swales, separators and grading transitions to existing slopes are also included within the proposed carriageway.
0 143 5 2 4 1 1420 14150 141 5 140 1400
SECTION 1B
Typical roadway cross sections have been developed for each of the roadway classifications identified. Graphical depictions of the typical roadway sections are provided in Figures 3132 and 35-43: Roadway Sections. The following are some of the critical design components factored into the roadway cross sectional design:
Vehicular Lanes. Travel lanes for vehicles have been provided at 3.0 meter widths for all road classifications, except 3.5 meter widths for arterial roads.
N
Pedestrian Walkways. Along the proposed roadway classifications a 2.0, 3.0 and 7.0 meter wide pedestrian walkways are proposed to facilitate the high levels of pedestrian movements expected in the City Center. For safety, the pedestrian pathway is typically separated from the vehicular lane by a planting/landscape buffer. The pedestrian walkway is also typically located to the outside of the roadway section so that there is less of a speed differential between the bike and pedestrian use. Vertical Design. In order to match the natural slopes of the hillsides within the Kimihurura area, all of the proposed roadway sections incorporate grading techniques to minimize disturbance of existing hillsides. Elements such as sloping vegetated/landscape areas, vertical curbs between pedestrian and bicycle lanes, and cross sloping the travel lanes in the same directions as the existing slope have been employed where ever practical.
FIGURE 29: KIMIHURURA ROADWAYS
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KIMIH U RU RA KI G A L I S U B A RE A P L A N N I N G
1.0m
1.0m
2.0m
2.0m
3.0m
3.0m
2.5m
2.0m
2.0m
1.0m
1.0m
Dry Utility
Grade
Pedestrian
Planted Swale
Vehicular Lane
Vehicular Lane
Parallel Parking on Pervious Pavers
Planted Swale
Pedestrian
Grade
Dry Utility
20.5 m Thoroughfare (R.O.W.)
FIGURE 30: ROADWAY SECTION 1A, LOCAL ROADWAY. This roadway is intended for neighborhood traffic in Sub Area. The section incorporates two-way traffic with one lane dedicated to each direction and also includes a parallel parking lane on one side. It incorporates permeable pavers in the parking lane which will allow runoff from the pavement to infiltrate into the ground. Pedestrian pathways and vegetated swales are located on each side of the section. It is assumed that bikeway traffic will share the road in low speed roadways like this.
FIGURE 33: THE KIMIHURURA PROMENADE (sections shown on next page) will have limited automobile access on some blocks.
FIGURE 34: THE KIMIHURURA PROMENADE (sections shown on next page) will promote pedestrian zones on most blocks.
Optional Additional Parking
2.0m
2.0m
1.0m
3.0m
1.0m
3.5m
1.0m
3.0m
3.0m
1.0m
4.5m
2.0m
2.0m
2.0m
2.0m
1.0m
3.0m
Grade
Pedestrian
Grade
Bike
Turf Shoulder
Planted Swale
Turf Shoulder
Vehicular Lane
Vehicular Lane
Turf Shoulder
Planted Swale
Pedestrian
Grade
Grade
Pedestrian
Grade
Bike
29.0 m Thoroughfare (R.O.W.)
FIGURE 31: ROADWAY SECTION 1B-1, FUTURE LOCAL ROADWAY. This roadway is located at the south side of the site and will allow for traffic flow from east to west along the south side of the site. It collects traffic from the arterial roadway running north to south through the site and will connect traffic to the residential areas adjacent to Kimihurura and to other destinations outside the City Center. This section has two-way traffic with one lane dedicated to each direction. A pedestrian walkway and bike path is located on the same side of the section; and there is a pedestrian pathway also located on the uphill side of the road.
1.0m
1.5m
3.0m
Turf Pedestrian Parallel Parking on Pervious Shoulder Shoulder Pavers
3.0m
3.0m
1.0m
4.5m
2.0m
2.0m
Vehicular Lane
Vehicular Lane
Turf Shoulder
Planted Swale
Pedestrian
Grade
29.0 m Thoroughfare (R.O.W.)
FIGURE 32: ROADWAY SECTION 1B-2, FUTURE LOCAL ROADWAY. This variation on 1B incorporates a retaining wall, and pervious parallel parking lane for more narrow parts of the section.
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I N FRASTR UCTURE T RA NSPORTATION
3.0m
2.0m
2.5m
2.0m
3.0m
3.0m
2.0m
2.5m
2.0m
3.0m
3.0m
6.0m
7.0m
6.0m
3.0m
Pedestrian
Trees in Pervious Pavers
Parallel Parking on Pervious Pavers
Bike Lane
Vehicular Lane
Vehicular Lane
Bike Lane
Parallel Parking on Pervious Pavers
Trees in Pervious Pavers
Pedestrian
Pedestrian
Pervious Paver Plaza (Water Features & Trees)
Pedestrian & Bike Promenade
Pervious Paver Plaza (Water Features & Trees)
Pedestrian
25.0 m Thoroughfare (R.O.W.)
25.0 m Thoroughfare (R.O.W.)
FIGURE 35: ROADWAY SECTION 2A. PROMENADE. This roadway section will be used along the major roadway that connects the Government Circle to the Kimihurura Roundabout. There are several variations of the roadway section depending on the block and specific area. The base section, which allows vehicular traffic, includes four lanes of travel, two in each direction, with a landscaped median located along the outside edge of both sides of the section. Pedestrian walkways and bike paths are then located outside the medians on both sides. It is found in the central portion of the Promenade.
FIGURE 36: ROADWAY SECTION 2B. PROMENADE. In the variations of the Promenade, the street is closed to vehicular traffic and the streetscape includes a variety of features that make it a real “People Place”. This variation shows fountains/water features located within the pedestrian promenade, along trees on pervious pavers providing shade. Additional pedestrian area with kiosks or sculptures and trees in place of a landscaped median, pervious pavers with landscaping and parking in the median area, and pervious pavers with patios and picnic tables with trees in the median area.
3.0m
6.0m
7.0m
6.0m
3.0m
3.0m
6.0m
7.0m
6.0m
3.0m
Pedestrian
Pervious Paver Plaza (Outdoor Patio & Trees)
Pedestrian & Bike Promenade
Pervious Paver Plaza (Outdoor Patio & Trees)
Pedestrian
Pedestrian
Pervious Paver Plaza (Kiosk & Trees)
Pedestrian & Bike Promenade
Pervious Paver Plaza (Sculpture Garden & Trees)
Pedestrian
25.0 m Thoroughfare (R.O.W.)
FIGURE 37: ROADWAY SECTION 2C. PROMENADE. In the variations of the Promenade, the street is closed to vehicular traffic and the streetscape includes a variety of features that make it a real “People Place”. This variation shows trees providing shade, along with patios and picnic tables on pervious pavers in the median area.
25.0 m Thoroughfare (R.O.W.)
FIGURE 38: ROADWAY SECTION 2D. PROMENADE. In the variations of the Promenade, the street is closed to vehicular traffic and the streetscape includes a variety of features that make it a real “People Place”. This variation shows kiosks, public sculpture and trees in the median area.
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KIMIH U RU RA KI G A L I S U B A RE A P L A N N I N G
3.0m Pedestrian
2.0m Trees in Pervious Pavers
2.5m Parallel Parking on Pervious Pavers
2.0m
3.0m
Bike Lane
Vehicular Lane
3.0m Vehicular Lane
2.0m Bike Lane
2.5m Parallel Parking on Pervious Pavers
2.0m
3.0m
2.0m
2.5m
2.0m
3.0m
3.0m
2.0m
2.5m
2.0m
3.0m
Pedestrian
Trees in Pervious Pavers
Parallel Parking on Pervious Pavers
Bike Lane
Vehicular Lane
Vehicular Lane
Bike Lane
Parallel Parking on Pervious Pavers
Trees in Pervious Pavers
Pedestrian
3.0m
Trees in Pervious Pavers
Pedestrian
FIGURE 39: ROADWAY SECTION 3A, GREENWAY. This roadway section is is located in the center of the site and will be used to provide a connection from the Government Circle to the south Central Parks. It provides two lanes of vehicular traffic with a shady, lush green walk/bikeway.
Pedestrian
2.0m Trees in Tree Grate
6.0m Diagonal Parking
2.0m
2.0m
3.0m
3.0m
2.5m
2.5m
2.0m
2.0m
1.0m
Pedestrian
Planted Swale
Vehicular Lane
Vehicular Lane
Parallel Parking on Pervious Pavers
Planted Swale
Pedestrian
Bike
Grade
25.0 m Thoroughfare (R.O.W.)
25.0 m Thoroughfare (R.O.W.)
4.0m
1.0m Grade
3.0m Vehicular Lane
3.0m Vehicular Lane
21.5 m Thoroughfare (R.O.W.)
FIGURE 40: ROADWAY SECTION 3B, MINOR COLLECTOR. This section is located on roadways both north and south of the Promenade, running parallel with it. They provide access from the Mixed Use Commercial area of the Sub Area to the arterial roadway and the major collector at the north end of the site, as well as access to the back sides of the buildings in this area. They include two way traffic for both vehicular and bikes, parallel parking on both sides of the street and pedestrian walkways adjacent to the proposed buildings.
6.0m Diagonal Parking
2.0m Trees in Tree Grate
4.0m Pedestrian
30.0 m Thoroughfare (R.O.W.)
FIGURE 42: ROADWAY SECTION 4A AND 4B, MAJOR COLLECTOR. This roadway is a large loop road located at the northern end of the site, linking to the northern neighborhoods The section incorporates two-way traffic with one lane for each direction of travel with a second lane located in some areas to allow for a left turn lane. As shown above, diagonal parking lanes are also located on both sides of the roadway where it runs through the commercial district/ Plaza that anchors the promenade (shown above in section 4A). Pedestrian walkways and bike paths are located on either side of the roadway. Along 4B (not shown) the major collector section would not have diagonal parking on either side.
Park
FIGURE 41: ROADWAY SECTION 3C, MINOR COLLECTOR. This roadway is located in the southwest part of the site. It collects traffic from residential neighborhoods, linking them to the north/south arterial. It contains two way vehicular traffic, on street parking, and two vegetated swales. A pedestrian way is on one side of the section and ped/bikeway on the other.
2.0m
3.5m
3.0m
1.0m
3.0m
3.0m
3.0m
3.0m
3.0m
1.0m
3.0m
2.0m
Pedestrian
Bike
Planted Swale w/ Large Trees
Turf Shoulder
Vehicular Lane
Vehicular Lane
Planted Swale or Turn Lane
Vehicular Lane
Vehicular Lane
Turf Shoulder
Planted Swale w/ Large Trees
Pedestrian
30.5 m Thoroughfare (R.O.W.)
FIGURE 43: ROADWAY SECTION 5, ARTERIAL. This roadway is the main thoroughfare through the site, and allows travel to and from the north and the south sides of the site. The section has four lanes of travel, two in each direction, with a landscaped median separating the travel directions. Landscaped medians are located along both sides of the roadway along with large vegetated swales and pedestrian walkways and bike paths.
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I N FRASTR UCTURE DR A I NAGE
Rainfall (mm)
5 147
14 60 1 475
14 55
1470
50
146 5 AESTHETIC STORAGE 1460 POND
1455
1972-2002 Rainfall Average
140 120 100 80 60 40 20 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec FIGURE 44: MONTHLY AVERAGE RAINFALL DATA IN KIGALI CITY FROM 1972-2002
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Rainfall Characteristics. Kigali is located in the African Sub-Sahara where rainfall is approximately 1000 mm per year; however, the high altitudes of the region cause temperatures and rainfall to be more moderate than some of the hot and humid equatorial regions surrounding Kigali. The seasons in Kigali can be characterized by two rainy seasons, and two dry seasons. The rainy seasons occur from late February to May and October to December with April and November being the wettest months, and the two dry seasons occur from June through September and from January to late February. During the dry seasons, rainfall is minimal and can often times be completely absent. Refer to Figure 29 for Average Annual Rainfall Data in Kigali City.
75
160
P L AN N I N G AS S UM P TIO N S
14
180
1495
65 14
Improvement and creation of wetland areas through constructed wetlands and bio-retention areas will help attain the goal of wetland restoration and preservation and will be in line with Rwanda’s effort to create wetland preservation zones in some of its more developed areas. The stormwater
14 14880 5 14 90
70 14
Stormwater plays a major role in the success of the development of Kimihurura. Establishing drainage ways to convey runoff and control erosion are two key aspects to the stormwater plan. The Kimihurura Sub Area is an urban city center that does not currently have a comprehensive stormwater management plan or significant stormwater infrastructure. Well designed stormwater management plans and well implemented stormwater infrastructure are essential in establishing a higher quality of life for a community. The approach for the drainage planning in Kimihurura will include prioritization of areas for stormwater management with the goals of sustainability, erosion control, and resource preservation in mind.
design for Kimihurura also involves planning for increased population with more sophisticated drainage techniques and infrastructure that will work with a more urban landscape by using subsurface infrastructure as a conveyance tool in appropriate areas.
75
PLA NNING
Runoff Characteristics. The Kimihurura site is divided into two drainage basins which are separated by a ridge that runs along the western portion of the site and divides the site into one large basin on the east side and a smaller basin in the northwestern portion of the site. Historic runoff sheet flows over the site or flows in naturally formed ditches along the roadways and discharges into the existing wetland area south of the site. Offsite flows may be a consideration from the north; however, the anticipated area of inflow is small. Kimihurura is an urban area with a fairly developed system of paved and unpaved roadways. Vegetation is limited to native grasses and smaller vegetation with limited areas of larger and dense trees because of the more urban feel of the area. Slopes on the Kimihurura site are considerably flatter than on some of the other sites in Kigali, with the majority of slopes falling in the 5% to 10% range.
1450
1445 SEDIMENTATION BASIN SB-1 BIORETENTION AREA
1440 35 14 1430
1425 1420 1415 1410 1405
LEGEND EXISTING DRAINAGE SWALE PROPOSED DRAINAGE BASIN PROPOSED DRAINAGE SWALE PROPOSED DRAINAGE PIPE ENVIRONMENTAL TRANSITION ZONE (ETZ) DRAINAGE FLOW
N
CONSTRUCTED WETLANDS IN ETZ CW-1
STORMWATER STORAGE ZONE
FIGURE 45: OVERALL DRAINAGE NETWORK PLAN
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KIMIH U RU RA KI G A L I S U B A RE A P L A N N I N G
P R O P O S E D C O N V E YA N C E PATTE RN S CALCULAT ION S A ND DESIG N C R IT ER IA Calculations were prepared in compliance with the Study of Stormwater Drainage Management and Erosion Control for Kigali City, Technical Study Report, Volume 1, August 2007. Based on the criteria, proposed drainage facilities are sized using a 10-year frequency design storm with runoff calculations completed using the Rational Method. The Rational Method can be represented by the following formula:
Q = CiA. Where Q is the flow rate in liters/second; C is the runoff coefficient; i is the rainfall intensity in liters/ second*ha, and A is the area in hectares. The runoff coefficient is determined using an assumed land plan use with proposed density to determine the impervious area over the site with a given coefficient of runoff depending on the proposed surface. For calculation purposes, the existing site’s C value was estimated at approximately 0.35 because existing development is somewhat dense with existing roadways and buildings but still has considerable unpaved surfaces. For the proposed condition, the C values were assumed to be approximately 0.70 for both basins because impervious surface will be added with the proposed roadway improvements. These values are lower than previously assumed in the Technical Study Report prepared in August of 2007 by NORPLAN because they are based on actual development plans that incorporate more pervious areas with the incorporation of parks and athletic field facilities. The anticipated program for the Kimihurura site includes additional roadway infrastructure which will create access to improved and new government buildings and other business and commercially related infrastructure. Intensity values, i, are based on historic rainfall data collected and analyzed over a period of time shown in Table 4. The goal of analyzing the existing and proposed runoff using the Rational Method is to determine what is required to mitigate flows such that the proposed runoff does not create point sources or exceed the historic runoff. In order to attenuate the flows, constructed wetlands and detention facilities will be used on the Kimihurura site to ensure that flooding downstream does not become a problem and that the quality of the runoff is improved prior to discharging from the site. Table 5 shows the results of the Rational Method Analysis of the historic and proposed site runoff along with the detention that will be utilized to control the stormwater flow.
Controlling stormwater through the Kimihurura site will require a combination of sustainable and simple surface drainage techniques along with underground piping and conveyance systems in the more restricted and urban portion of the site. Stormwater runoff at the northeast portion of the site, in the proposed convention center region (see site sections, Figures 36-38, and 42-43, as well as Figure 29: Kimihurura Roadways, in the transportation section of this report), will need to be controlled through the installation of stormwater inlets and underground or covered conveyance pipes. This is a necessary step in the design for this area because the roadways planned incorporate curbing, sidewalks, and other hardscape features that prohibit the installation of roadside ditches. Using nonsurface drainage in central and highly visible areas, such as near the Convention Center, will also add to the aesthetic and functional value of the overall site. The stormwater infrastructure from the Convention Center site should discharge into a proposed aesthetic/water quality pond located within the proposed Park. The Park is located along the east side of the main arterial roadway that runs north to south through the site (road section 5 on Roadways Figure 43 in the Transportation Section of this report). The pond will need to be incorporated into the proposed Park program while providing storage volume for the drainage basin runoff. A vegetated collector swale will need to continue through the park area to convey outflow from the aesthetic pond to the proposed constructed wetlands located at the southeast corner of the site. Velocities will need to be dissipated as flow moves through the swale. Small bio-retention areas placed within the alignment of the swale will provide the damming needed to slow the flow and add an aesthetic landscaped feature to the greenway. Stormwater runoff from the northwest portion of the site, near the existing Government Circle will need to be directed into a separate sub basin. This flow will be captured by a vegetated swale with check dams located along the circular local roadway
concentric to the Government Circle (roadway section 1A on Roadways Figure 30 in the Transportation Section of this Report). A small sedimentation basin should be planned for the southwest corner of the site to capture this flow.
TABLE 4: PRECIPITATION FREQUENCY DATA, KIGALI AIRPORT 5 YEAR RETURN PERIOD (l/s-ha)(1)
10 YEAR RETURN PERIOD (l/s-ha)(1)
15
232
258
30
169
188
45
129
144
60
103
115
75
85
95
90
73
82
DURATION (min.)
Stormwater Practices and Erosion Control. The overall Stormwater Management Plan for the Kimihurura site will need to incorporate many types of drainage practices in order to adequately and aesthetically control stormwater. At a minimum, these practices should include the following: Underdrains. Some proposed roadway sections include landscaping within areas of pervious pavers or other areas where vegetated swales are not feasible and piping is not necessary. In these areas underdrains can be considered under the landscaping and parking areas where the proposed surface treatment is a paver that will allow runoff to infiltrate. The Underdrain Pipe. This pipe should be perforated to intercept flows that do not infiltrate the ground. They will flow downhill and daylight into a proposed vegetated swale. The size of the underdrain pipe will need to be considered in design as infiltration rates are very low. It may be necessary in some areas to install a larger perforated pipe in order to force stormwater flow away from the surface and towards its discharge point in high intensity storm events. Sizing of these facilities will need to be based on infiltration rates, and specific area runoff. Constructed Wetlands. Kimihurura is surrounded by many areas that have been designated as wetlands and within a flood plain. These wetlands remain dry for much of the year. They have been degraded downhill of the site due to industrial development. Constructed Wetlands (Figure 47)can be used in place of sedimentation or detention ponds as a storage and water quality treatment practice. Constructed Wetlands are more advantageous in this location due to their proximity to existing wetlands. They can also provide future opportunities for land use improvements and wetland restoration just south of the current Kimihurura site. This wetland will be coupled with a sewage treatment facility to be part of an Environmental Treatment Zone.
(1) Kigali Meteorological institute
TABLE 5: PRECIPITATION FREQUENCY DATA, KIMIHURURA NEIGHBORHOOD
10-YEAR RUN OFF (l/s)(1) EXISTING
PROPOSED
DETENTION REQUIRED (m3)
AREA 1
2,442
4,691
3,223
AREA 2
5,472
10,491
7,222
(1) Kigali Meteorological institute
PERFORATED DRAIN PIPE (SIZE TO BE DETERMINED) FREE DRAINING MATERIAL
PERVIOUS PAVERS
PEDESTRIAN PATH
TRAVEL LANE
GEOTEXTILE/FILTER FABRIC CLEAN GRAVEL AROUND PIPE
FIGURE 46: UNDERDRAIN DETAIL
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I N FRASTR UCTURE DR A I NAGE One Constructed Wetland area should be placed at the southeast corner of the Kimihurura site where it will serve as a discharge point for runoff from the eastern basin. An outlet will be need to be designed for overflow conditions so that water can pass more quickly and outlet to the existing wetland area. Periodic maintenance will be required to remove accumulated sedimentation from the Constructed Wetland treatment area. Bio-retention Areas. Bio-retention areas are similar to constructed wetlands, because species that are indigenous to wetland areas need to be planted within the targeted treatment area. Unlike constructed wetlands, bio-retention areas are not necessarily constructed adjacent to existing wetlands, and are also smaller in size. The intention is for stormwater to enter the treatment area where it will be retained for a period of time, allowing either sediment to settle, vegetation to uptake the water, or for infiltration into the ground. A perforated pipe surrounded by stone will need to be placed at the bottom of the bio-retention areas and directed downstream. All water that is not infiltrated or used for plantings will be daylighted to a discharge point. The plant species for the bio-retention areas must be selected carefully in order to withstand both periods of flooding and lengthy dry periods. Many mesic plans will fit this criterion, and native species to the land should be selected. See Figure 48: Bio-Retention Detail Aesthetic Storage Pond. A water-feature like pond will be used in the proposed park area to provide stormwater storage without compromising the aesthetic value of the park. This pond will contain dead pool storage that will remain at all times and will provide the aesthetics of the pond. An area above the designated standing water elevation will be allotted for stormwater storage and retention. Flow will enter the pond for treatment and exit into the collector swale for discharge into the constructed wetlands. See Figure 49: Aesthetic Storage Pond.
NATURAL WETLANDS CONSTRUCTED WETLAND
COMPACTED EARTH GRASS LINED OR RIP-RAP AS REQUIRED
FREE-DRAINING MATERIAL
FIGURE 47: CONSTRUCTED WETLAND DETAIL WIDTH PER DITCH DETAIL NATIVE PLANT SPECIES (MESIC)
STORAGE VOLUME NORMAL POND DEPTH FREE-DRAINING MATERIAL GEOTEXTILE FABRIC
0.5m COMPACTED EARTH
GEOTEXTILE FABRIC LINER
GRAVEL DRAIN PIPE TO DAYLIGHT DOWNHILL IN DITCH
FIGURE 48: BIO-RETENTION DETAIL
Vegetated Swales with Check Dams. Vegetated swales along the proposed roadways should be utilized, where acceptable, to direct flow away from vehicular and pedestrian travel areas, reduce erosion, and force flow towards proposed treatment and storage areas. The swales will also need to include check dams or drop structures at determined intervals to help with flow velocities. The structures will also provide small storage areas within the vegetated swales where sediment can settle out and stormwater can infiltrate the ground. See Figure 50: Vegetated Swale.
AESTHETIC STORAGE POND - FIGURE XX-XX
COMPACTED EARTH
FIGURE 49: AESTHETIC STORAGE POND
For the western portion of the site, roadside vegetated swales will be utilized to convey flow into a proposed sedimentation basin where it will be treated for water quality. A key to the success of using road side swales is “sizing�. The runoff from each contributing area will need to be determined in order to approximately size the swale for adequate capacity available in the allotted space. If the size needed to convey the contributing flow is not available, piping and other alternatives will need to be considered as a supplementary way to control the runoff.
Sedimentation Basin. A small sedimentation basin will need to be located at the south western corner of the site to collect stormwater runoff from open ditches and underground pipes on the western side of the site. See Figure 51: Sedimentation Basin Detail
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KIMIH U RU RA KI G A L I S U B A RE A P L A N N I N G
3m
STABILIZATION WITH VEGETATION
TRASH RACK 2 OUTLET STRUCTURE
1
3
NATIVE IMPERVIOUS FILL
1 0.5m
0.5m 4:1
SL
OP E
4:1
SL
BOTTOM OF POND
E OP
OUTLET PIPE STABILIZATION OUTLET TO EXISTING DRAINAGE
0.5m
FIGURE 50: VEGETATED SWALE
FIGURE 51: SEDIMENTATION BASIN DETAIL
WATER REU S E A ND C OLL E C T I O N Stormwater collection and rain water harvesting are highly feasible in a climate like Rwanda, where a significant amount of rainfall occurs at a specific time of year. This produces excellent opportunity to collect and store stormwater for use in drier seasons. At Kimihurura, there are two different conceptual possibilities for collecting, harvesting, and reusing stormwater. If both of these methods are implemented, water requirements for irrigation, toilets, urinals, and other non potable uses can be drastically reduced and more extensive irrigation systems can be considered. Firstly, rainwater harvesting from roof top runoff is a highly feasible way to collect a significant amount of water during the rainy seasons of the year. Despite the smaller roof top areas per capita that are associated with multi-story type buildings proposed at Kimihurura, collection of water from rooftop runoff is still highly feasible. Instead of trying to convey the runoff from the roof top areas to a central collection system for use over the entire site, it is much more practical to use the runoff collected from rooftops in areas surrounding the collection points. Collected runoff from roof tops can be used for irrigation surrounding the buildings it was collected from or it could be recycled for use in toilets and other grey water practices within the building itself. A second method for stormwater collection and reuse is to use stormwater flows collected in the pond, sedimentation
pond, and constructed wetlands for irrigation in the park and athletic field areas. Since an aesthetic pond with dead pool storage is already proposed within the park area, an excellent opportunity for recycling this water into irrigation for the park itself is presented. In both these cases, calculations will be needed to determine the quantity of water that is available through both roof top rainwater harvesting and stormwater collection. Additionally, this quantity would need to be compared to water demands for irrigation and grey water use to determine its viability. These practices should be a strict requirement of development. Phasing. The majority of the development in Kimihurura will be completed at one time, with the exception of the main arterial roadway running north to south along the center of the site (roadway section 5 on Figure 43: Kimihurura Roadways in the Transportation Section of this Report). This roadway is expected to be constructed first with the remainder of the development to follow. Any associated drainage should be installed at the time the roadway is constructed and a portion of the constructed wetlands should be built in order to accommodate the additional flow. The vegetated collector swale, along with the bio-retention areas located with the swale, should also be constructed so that flow from the roadway can be collected and treated and minimal earthwork will be required near the roadway for future drainage.
FIGURE 52: AESTHETIC STORAGE POND
FIGURE 53A: CONSTRUCTED WETLAND
FIGURE 53B: VEGETATED OR BIO-SWALE
K I M I H U RU RA - I NFRA STRU C TU RE 5-23
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I N FRASTR UCTURE WAT E R Sub Area, planning, reuse and rainwater harvesting will need to be incorporated into the plan. A minimum water service line size can be deduced using typical water pipeline velocities of 5 ft/s – 7 ft/s (1.53 m/s – 2.13 m/s). The minimum pipe size for the Kimihurura Sub Area should be 150 mm. This will allow adequate capacity for additional growth in the area.
Water treatment is provided by the Kimisagara Water Treatment Plant in the Nyarugenge District. The Kimisagara Water Treatment Plan currently operates at 22,000 m3/d at nearly its design capacity of 24,000 m3/d. The treatment train is conventional clarification-filtration-disinfection with permanganate, polymer, and aluminum sulfate as coagulants.
A new 300mm transmission line is being proposed from the updated Remera Stade tank site to the Kimihurura neighborhood. This will provide adequate flow to serve the new development. Smaller distribution lines from 150200mm will loop through the proposed development. Figure 54 depicts the proposed layout of the water system.
The projected population for the Kimihurura Sub Area is shown in Table 6: Population And Service Assumptions. Using this information, a projected water demand has been calculated (see Table 7). MININFRA has established a design range of 80 lpcd to 200 lpcd. Data shows a usage of 200 lpcd in houses with plumbing, as well as in high standing neighborhoods. Kigali wants average usage to be at 80 lpcd, which is what this analysis shows. To accomplish this within the Kimihurura 5-24 KIGALI S UB AREA PLANN IN G
5_KIMI_Book.indb 24
CONNECT TO EXISTING WATER SUPPLY SYSTEM CONNECT TO PROPOSED WATER SUPPLY SYSTEM
70 14 5 147
EXISTING 1000 m3 TANK
1500 1495
90 14 1 485 1480
14 75
According to maps provided by ElectroGaz, the Kimihurura Sub Area has potable water infrastructure currently available to support the proposed long term growth and development for the area, however, additional infrastructure (water storage, pump stations, etc.) will be required to enhance the capacity of the system. The larger pipe sizes range from 125mm to 200mm. Sections of water pipeline will need to be removed and/or relocated due to conflicts with proposed buildings.
PRO JEC T ED WAT ER D EMAN D
CONNECT TO EXISTING WATER SUPPLY SYSTEM
P R O P O S E D S Y S T E M D E S IGN The Kimihurura Sub Area is located within the Kimisagara water zone as delineated on the ElectroGaz master water drawing. Proposed development in the area will result in the creation of one new pressure subzone. A 1000m3 storage tank (Kimihurura) and pumping facility currently service the area. Because this tank is at a lower elevation than the majority of the proposed Kimihurura neighborhood, additional storage is being proposed at a tank site northeast of the proposed development. This existing tank (Remera Stade) has a capacity of 150m3, and sits at an elevation of 1527m. By increasing the storage capacity at this site, even though it’s in a separate ElectroGaz pressure zone, a gravity system can be utilized to service the Kimihurura neighborhood.
EXISTIN G WAT ER S U PPLY & TREATMENT
EXISTING 150m3, ELEV= 1527M EXPAND TO A 1900 m3 TANK
1460 146 5
The Kimihurura Sub Area, approximately 89 ha (218 acres) in size, is located in one of the more urbanized areas of Kigali. The site is centered atop of Kimihurura Hill, surrounded by lowlying wetland areas 90m (295 ft) below. The Kimihurura Hill is almost entirely developed with residential neighborhoods, government facilities, commercial businesses and civic center’s already constructed, along with a new hotel and conference center that is currently under construction. Elevation ranges within the proposed boundary range from about 1450m elevation to 1500m elevation.
LOW PRESSURE WATER SUPPLY ZONE 40PSI (275.8kPA) PRESSURE ZONE
14705 1144660 1455 1450 445 1 440 1 435 1 0 144325 11420 1441150 11405 1400
Additional water storage will need to be provided for the site in order to provide enough capacity for peak day flows and fire storage. A total of approximately 2000 m3 will need to be provided, which will be in addition to the existing 150 m3 tank. Because the Kimihurura neighborhood has a maximum elevation of 1500m, a minimum of 40 psi of theoretical static pressure can be provided using gravity flow. Table 8 depicts preliminary water storage requirements. Design assumptions for storage include:
80PSI PRESSURE ZONE
HIGH PRESSURE WATER SUPPLY ZONE
LEGEND 300MM HIGH PRESSURE WATERLINE 200MM HIGH PRESSURE WATERLINE EXISTING WATERLINE
N
FIGURE 54: KIMIHURURA WATER SYSTEM
6/17/2010 8:08:56 PM
KIMIH U RU RA KI G A L I S U B A RE A P L A N N I N G
• • •
Hotel sites will have sprinkler systems Storage for a peak day of residential usage is being provided. Fire flows will be 125 l/s based on a reduction of fire flows due to sprinklering.
DESIGN A PPR OA C HES & A SSU MPT ION S
TABLE 6: POPULATION AND SERVICE ASSUMPTIONS DEVELOPMENT
RESIDENTIAL
CLASSIFICATION
RESIDENTIAL
840
HOTEL ROOMS
1500
COMMERICAL (2)
120
TOTAL
•
(1) Assumes 4 people/unit residential _2 people unit/hotel
•
•
•
•
•
•
0
3360 3000
225000
1800
With the addition of the 300mm waterline and increased storage at the Remera Stade tank site, adequate capacity can be provided to the Sub Area. Although the Kimihurura Sub
8160
(2) Commercial space is 225,000 sq. meters; assume 1 equivalent residential unit per 500 sq. meters
TABLE 7: PRELIMINARY WATER REQUIREMENTS. PUMPING & TREATMENT FACILITY DEVELOPMENT CLASSIFICATION
nearly neutral pH, and is free from disinfection by-products, salts, minerals, and other natural man-made contaminants. Plants thrive under irrigation with stored rainwater, and with the majority of Kigali’s population in the business of subsistence agriculture; rainwater harvesting could provide the necessary water storage to be utilized during the dry season. Rainwater harvesting shall be prioritized for buildings in Kimihurura. The main uses for rainwater will include secondary usage of bathroom facilities, as well as flushing water for toilets in individual hotel rooms and conference facilities. Additionally, irrigation will be a secondary usage of harvested rainwater. Water Reuse. The 80 l/d per person estimates do not allow for a great deal of outside irrigation associated with hotel residential and commercial properties. Reuse on a site-by-site basis is critical to minimizing pumping and storage facilities. The wastewater section will review this in more detail.
SU STA IN A BLE S OLU T IONS Rainwater Harvesting. Implementation of rainwater harvesting can also provide additional water storage to the Sub Area of Kimihurura. Rainwater is valued for its purity, with a
Area has space limitation, attempts should be made to provide for future infrastructure by reserving land for utility corridors and water system infrastructure (pump stations, storage, treatment, and fire fighting).
SU MMA RY
The design approaches and assumptions for the Kimihurura Sub Area developments are as follows: Water pipeline connections will be looped from proposed transmission main line in order to produce a more dependable distribution network. This will allow particular sections of the network to be isolated and repaired in the event of failure without affecting the entire network. Water pipeline connections that cannot be made from existing waterlines will be connected to the nearest water treatment plant, reservoir, or viable water source. Existing water pipeline and reservoirs are to remain where possible in order to accommodate the proposed development. Water pipelines to be laid along the “uphill” side-table of existing and proposed roads for easy access of installation and maintenance, providing a minimum of 3m of horizontal clearance from sanitary pipelines. The Ministry of Infrastructure (MININFRA) has promoted a city-wide goal of 80 lpcd (Liter per capita per day) for unit water demand. Office buildings, larger homes, new residential developments, and tourism facilities may use up to 200 lpcd. Attempts should be made to provide for future infrastructure by reserving land for utility corridors and water system infrastructure (storage, treatment, and firefighting).
POPULATION (1)
COMMERCIAL
The first phase of development will be adjacent to the eastern roundabout, and will be serviced by a loop connection from the existing 200 mm water line.
P H AS I N G
RESIDENTIAL HOTELS COMMERICAL TOTAL
EQUIVALENT
PEAK
FIRE
PEAK DAILY
RESIDENTIAL
DAILY
STORAGE m 3 (!)
PLUS
UNITS
FLOW l/d
FIRE STORAGE m 3
840
403,200
900
1,303.2
1500
450,000
450.0
450
216,000
216.0
2,790
1,069,200
900
1,969
(1) Assumes 125 L/s demand for 2-hours
TABLE 8: PRELIMINARY WATER REQUIREMENTS. FINISHED WATER STORAGE FACILITIES EQUIVALENT
AVERAGE
PEAK
PEAK
PEAK
DEVELOPMENT
RESIDENTIAL
DAILY
DAILY
DAILY
INSTANT
CLASSIFICATION
UNITS EQRS
FLOW l/d
FLOW l/d
FLOW l/s
FLOW l/s
RESIDENTIAL
840
268,800
403,200
4.67
15.56
HOTEL ROOMS
1500
300,000
450,000
5.21
17.36
COMMERICAL
450
144,000
216,000
2.50
8.33
2,790
712,800
1,069,200
12.38
41.25
TOTAL
(1) Proposed Pumping Facilites Locations Not Finalized (2) Peaking Factor of 5 Used
Pumping and storage facilities could be phased for the demands but distribution facilities need to be built as presently proposed. K I M I H U RU RA - I NFRA STRU C TU RE 5-25
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I N FRASTR UCTURE 14 146
S ANI TARY SEWER
1 47
EXISTIN G S EW ER S U PPLY Currently, the Kimihurura Sub Area utilizes pit latrines, septic tanks, and open or direct discharge for wastewater management. Sanitary sewer and stormwater drains combine and are drained in a dual system to the wetlands or river systems below.
PRO JEC T ED S EW ER D EMAN D The design of the collection system shall use peak instantaneous flow criteria for pipe sizing and peak flow days for scour velocities. Pipe sizing shall be based on pipes at 50% full for collection lines and 75% full for interceptor lines. Sewage Treatment Plant sizing shall be sized for peak day usage. Table 9 summarizes peak and average daily flows. As compared to water usage, sewer capacity is 80% of water usage, or approximately 64 lpcd. Additionally, peak day flows will be 150% of average day flows, and peak instantaneous flows will be 500% of average.
P R O P O S E D S Y S T E M D E S IGN
14
5 47
According to PDA Kigali – Avant Project Sommaire, October 2008, a plan is being devised to provide wastewater to the City of Kigali. It is anticipated that the Kimihurura Sub Area will be able to tie into the new system. In the event that development precedes the availability of a wastewater system, interim measures will need to be taken. Such measures include temporary lagoon systems, constructed wetlands, and packaged treatment plants.
15
1495
90 14
Specifically, a central treatment and collection system is being proposed for the Kimihurura Sub Area. The STP system designs are proposed to occur in a phased approach with the ultimate system design that will serve the entire area. An 856 m3/d facility would be needed to treat the site demand, assuming some reuse.
1 485 1480
14 7
The Kimihurura Sub Area is centered atop Kimihurura hill, surrounded by low-lying wetland areas 90m (295 ft) below. The Kimihurura hill is almost entirely developed with residential neighborhoods, government facilities, commercial businesses and civic center’s already constructed, along with a new hotel and conference center that is currently under construction.
Figure 55: Kimihurura Sanitary Sewer System depicts the proposed wastewater system layout. Pipe sizes will range from the minimum 200mm to 250mm sizes. All development sites will drain by gravity except for the farthest west buildings, which will need to have their own small scale lift station to enable sewage to be treated at one facility.
1
0 143 5 142
TABLE 9: PRELIMINARY WASTEWATER REQUIREMENTS. COLLECTION & TREATMENT FACILITIES DEVELOPMENT
RESIDENTIAL
DAILY
DAILY
DAILY
INSTANT
CLASSIFICATION
UNITS EQRS
FLOW (l/d)
FLOW (l/d)
FLOW (l/s)
FLOW (l/s)
840
215,040
322,560
3.73
12.44
HOTEL ROOMS
1500
240,000
360,000
4.17
13.89
COMMERICAL
450
115,200
172,800
2.00
10.00
RESIDENTIAL
1420 1415 0 141 1405 1400
ETZ ZONE WASTE WATER LAGOON LOCATION
225000 SM TOTAL
2,790
(1) Wastewater assumed at 80% of water system estimates
570,240
855,360
9.90
36.33 LEGEND PROPOSED 200mm SANITARY SEWERLINE PROPOSED 250mm SANITARY SEWERLINE
N
(2) Peaking Factor of 5 used
5-26 KIGALI S UB AREA PLANN IN G
5_KIMI_Book.indb 26
FIGURE 55: SANITARY SEWER SYSTEM
6/17/2010 8:09:07 PM
KIMIH U RU RA KI G A L I S U B A RE A P L A N N I N G
FUTURE ROADWAY
DESIGN A PPR OA C HES A ND A S S U MPT IONS The design approaches for the Kimihurura Sub Area are as follows: • Sanitary sewers and storm sewers will be separated. • The sewerage system should be designed to flow by gravity to avoid having to pump sewerage throughout the system. • The sewer pipelines are laid along the “downhill” side of roadways, providing a minimum of 3m of horizontal clearance from water pipelines. (See Figure 57) • All sewage is transported by underground pipes and treated at the proposed Sewerage Treatment Plant (STP) or temporary lagoon, depending on the current phase of development. • After being treated, sewage effluent will be discharged into a constructed wetland to further eliminate nitrogen and phosphorus through natural biological processes. • Green buffer zone will be proposed surrounding the STP to allow the facility to blend in with the surrounding environment.
WASTEWATER LAGOONS 4
1
NATURAL DRAINAGE WAY / WETLANDS
3.0m
COMPACTED EARTH
FIGURE 56: PROPOSED SEWER TREATMENT PLANT SECTION
for secondary purposes, such as toilet flushing.
P H AS I N G Because Kimihurura is located on a fairly steep site, and has very little flat ground, a higher level of sewer treatment is necessary. As mentioned previously, a phased approach for
The design for the sewerage network complies generally with the design guidelines as stated in the PDA Kigali – Avant Project Sommaire, October 2008. Table 9B lists the design guidelines for the Kimihurura Sub Area.
TABLE 9B: SEWER DESIGN CRITERIA
Self cleansing velocity
Qpeak; V = 0.6 m/s for Q = Qpeak/10
SU STA IN A BLE S OLU T IONS
Minimum slope of the network(1)
0.50%
Minimum pipe diameter
200mm
Formula used
Manning-Strickler formula
Manhole location (1)
Maximum 120m spacing
Minimum cover(1)
90cm from the ground
Maximum cover(2)
5m
Choice of material
PVC for Ø 315 mm; Reinforced f from Ø water 00 lines – 3 m; Separation
A key component of the proposed system is to establish dual black and grey waste systems for individual buildings. This will provide the opportunity for grey water reuse, save money on capital costs as well as ongoing operation and maintenance costs for the STP. All major buildings should employ black water and grey water piping. The grey water effluent would be used primarily for irrigation around the facility as well as for public facilities such as the main park below the proposed convention center. Where possible, grey water should be used
4
1
PARAMETER
sewerage will be implemented. The first phase of the system will consist of an STP located south of the site along the main east-west thoroughfare. An aerated lagoon system coupled with constructed wetlands is being proposed. This is a more sustainable solution to treating sewerage from the Kimihurura Sub Area. This area will need to be approximately 2.0 Ha including the area for the clarifying pond using a 29 day detention time.
The first phase of development will be adjacent to the eastern roundabout, and will be need to be treated by either a smallscale onsite treatment facility, or by constructing the permanent proposed improvements in place up the first phase.
VALUE
V = 1.0 m/s for Q = 2/10 Qfull
Minimum service line pipe diameter = 100
TYPICAL WATERLINE LOCATION
TYPICAL SANITARY SEWER LOCATION
(1)Modified form PDA Kigali (2) Not a criteria from PDA
FIGURE 57: TYPICAL WATERLINE & SEWAGE LINE LOCATION
K I M I H U RU RA - I NFRA STRU C TU RE 5-27
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I N FRASTR UCTURE P OWE R/ DRY UTILITIES
This comparative exercise has been done for the sake of cost comparison and in order to help policy decisions, as well as to begin a discussion about alternative energy approaches in Rwanda. It is recommended that Kigali undertake a municipal or national level campaign to develop an Energy Policy that will place the issue of alternative energy and sustainability front and center.
The Kimihurura site is an existing city center with strong government and military presence. The Kimihurura plan will add both residential and commercial facilities to the area. Electrical, telephone and some fiber optics facilities exist in or around the area. The capacities of these facilities are unknown due to complexity of the usage from the site coupled with the adjacent neighborhoods. Power to the site includes a 15 KVA line that runs through the site along with distribution lines.
TABLE 10: POWER DEMAND FOR INDIVIDUAL FACILITIES
1450
1455 1460 1465 1470 75 14
75 14
EXISTING 15kV OVERHEAD ELECTRIC LINE
UNIT DEMANDS (W/m 2)
DEVELOPMENT
1495
CLASSIFICATION 90 14
RESIDENTIAL
10
HOTEL
20
COMMERICAL
15
TABLE 11: ESTIMATED POWER DEMAND AVERAGE POWER DEVELOPMENT
DEMAND
CLASSIFICATION
(mw)
RESIDENTIAL
1.235
HOTEL
1.548
COMMERICAL
3.750
TOTAL TOTAL WITH SUSTAINABLE SOLUTIONS
1485 1480
N TIO TA S B SU O P) D A N KO T M GI NSE O I T EE (S
1470 5 146 4 1 60 1455 1450 EXISTING 15kV OVERHEAD ELECTRIC LINE
6.530 (1)
4.400
LEGEND EXISTING OVERHEAD ELECTRIC LINE
GIKONDO SUBSTATION
5_KIMI_Book.indb 28
4 14 1
0 143 5 142 1420 14150 141 5 140 1400
(1) A reduction of one-third of the total demand has been applied to the sustainable
5-28 KIGALI S UB AREA PLANN IN G
1500
14 75
An alternative energy approach is discussed under Sustainable Solutions, which addresses Demand Reduction and Alternative Sources of Supply. Many of these approaches are just emerging, Sustainable Solutions may reduce power costs up to 25% to 30% in the long term, as shown in Table 11. Reductions primarily come from two sources when using sustainable/ renewable energy sources. First, although capital costs may be higher up front (costs of new technologies continue to decline with competition and innovation). Additionally, the life-cycle/ operational costs of maintaining and producing energy make them cheaper in the long run. Second, when using demand reducing technologies up front, BOTH capital and long-term life cycle/operating costs are reduced.
1445
E X I S T I N G P O W E R S UP P LY
147 0
This section addresses power, telephone, and internet within Kimihurura. Of these services, the main analysis discusses a conventional approach to power supply, which is also costed in the Capital Improvements Plan/Municipal Financing section below. This includes power plants, substations, and power distribution loops/lines. This analysis shows a “worst case scenario” for costs; however many sustainable options exist which will also improve overall costs
N
PROPOSED UNDERGROUND ELECTRIC LINE
FIGURE 58: KIMIHURURA POWER PLAN
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KIMIH U RU RA KI G A L I S U B A RE A P L A N N I N G
PRO JEC T ED POW ER D EM AN D The proposed site will require an upgrade to the electrical grid. It appears that the site is serviced by the Gikondo substation. A new buried distribution system is proposed for the Sub Area. Figure 58 depicts that layout of the electrical system. Improvements beyond the Kimihurura area will not be addressed in this report. Power demand for the site will be estimated using watts/ square meter (W/m2), for the individual land uses that are outlined in Table 10. Based on the total demand for the site improvements, the average power demand for the planning area is outlined in Table 11. From the proposed site program and its associated demands no new substations are anticipated for the areas. From the site and its associated demands one main substation will be required for the site and surrounding areas. The main 15 KVA substation will be located along the main highway. Figure 58 outlines the substation locations. Phasing. Phasing for the project is anticipated to include the main roadway between the Government Circle and the existing traffic circle. Dry utilities can be easily be phased through this area.
SU STA IN A BLE S OLU T IONS The previous analysis as well as the cost estimates (see Capital Improvement Plan and Municipal Financing section) focused on conventional electrical scenarios for the production of power. However, because Kigali (and Rwanda in general) need such a high level of new energy, and because Rwanda has a stated national policy to reduce its carbon footprint, it is important to explore alternative energy sources. Table 11 outlines potential reductions if sustainable solutions are incorporated. To the right, new ideas in both cutting demand and expanding supply are presented.
R E DUC I N G DE M AND : E L E C T R I C AL E N E RGY EFFICIENCY Because of the rapidly increasing demand and cost for electrical power in Kigali, new development in the Sub Area must be energy efficient and lighten the new loads within the Sub Area. Multiple small savings at the individual building and residential units in aggregate can make a very large difference in energy consumption and the sizing of the electrical distribution system. Proper building design in solar orientation, materials, shading configurations and passive cooling strategies will make mechanical cooling largely unnecessary. As more residents move to automated washing and drying of clothing, laundry mats should be conveniently located in the neighborhoods for centralized services utilizing high efficiency washers and dryers. “EnergyStar” or similarly efficiency rated equipment and appliances are to be used throughout new developments, including especially water heaters (which may also be solar) and refrigerators. Lamps for light fixtures should be LED or compact florescent where ever possible. Alternative briquette, gas, oil or solar cookers will greatly reduce electrical demand. Thermal mass, radiant barriers, thermal insulation and vented skin technologies also serve to reduce requirements for cooling. Where some mechanical cooling is still desirable, low energy consumption techniques such as evaporative cooling, night time recharge, geothermal exchange, domestic water chill beam and other forms of radiant cooling are recommended.
A LTE RN ATIVE SO U RC E S O F S U P P LY In Kigali, where most the electrical power is from the burning of imported diesel fuel outside the Sub Area, alternative renewable energy sources are important to sustainable and independent development within the Sub Area. While some of the new technologies may seem to be more expensive than fossil fuel electrical generation, fossil fuels have “external” costs that are not computed into up front costs (such as environmental, political and health costs as noted in Chapter 2, Sustainable Urbanism). These hidden costs have important implications for long term national security and environmental sustainability as well as medical costs. Their hidden costs should be calculated into decisions about energy supply. In addition, there is important economic development potential for Rwanda by emphasizing green technologies. By using these technologies abundantly and developing prototypes, Rwanda can position itself as a leader in this arena and potentially develop a clean energy industry that can provide technology to the whole Central/East Africa region. The range of new/green energy technologies is growing exponentially. Solar photovoltaics (PV) can be mounted to roof tops or banked together in generation plants within each Sub Area. PVs can be used as roof shelters, park shade structures, window shades and even facades. Other renewable sources to be utilized within the Sub Area include: biogas and biomass generators from wet organic waste in the sewer system and dry organics (from such sources as market and produce processing waste) respectively. Gravity water flow from hilltop storage tanks in the Sub Area will generate electricity while reducing water pressure to appropriate levels.
Photovoltaic. Photovoltaic (PV) cells should be incorporated where feasible into individual buildings, including civic buildings. Although not as cost effective (at this time) as fossil fuel generation, it is expected that with the increased development in the City and the problems associated with electrical generation, PV’s would provide a reliable source. Thin film PVs can be applied to any exterior surface exposed to direct sunlight. As a matter of thumb, household energy needs can be met by reserving 9 m2 unit on a north or near north facing roof along with architectural design guidelines which will make the incorporation of solar energy more cost effective. Electrical Power “Smart” Grid. The state of the art in electrical power distribution flow is moving from the hierarchical large central power plant grid to a network grid for decentralized power generation sources. The integration of multiple renewable energy sources is changing the way distribution is achieved. The diversity of sources such as solar photovoltaic, wind, hydro and biofuels that may contribute inconsistent peaks in generation from different locations require a “smart” grid to balance loads from many sources and distribute them to where they are needed. Hydrogen generation is even being tested as an energy storage medium to offset the highs and lows of wind power generation. This kind of power grid will allow anyone to contribute it and be reimbursed through reverse metering.
K I M I H U RU RA - I NFRA STRU C TU RE 5-29
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DEVE LOP ME NT & DESIGN GU IDEL INE S DE S I GN GUIDELIN ES The roadways and circulation rights-of-way shown in the previous Infrastructure section, as well as the Open Space/ Greenway Zone form the framework of public space which is in the domain and responsibility of the municipal government. The site design of these areas has been set by the plan and will become a legal document if adopted by Parliament.
position in the Kigali landscape, and the need for it to link carefully to the design orientation of the new Convention Center/Hotel, it is recommended that detailed streetscape design guidelines be produced with recommendations for these elements Like detailed infrastructure design, this shall be undertaken before project commences construction.
However, attention to detailed design elements for the public area promenades, plazas, outdoor seating and eating areas, and garden/landscaped areas was beyond the scope of this study. This includes: lighting, signage and wayfinding, restaurant and shop display and facades, restaurant patio regulations and street furniture, paving, walls and steps, kiosks and detailed landscaping. Because of Kimihurura Sub Area’s prominent
After the infrastructure rights-of-way and the Open Space/ Greenway Zone, the remaining elements of the site include interior block layouts and buildings, which will be in the private domain. Private sector developers for these sites shall follow direction provided by zone in the Development Guidelines and general Design Guidelines shown below.
FIGURE 59: KIMIHURURA HIGH DENSITY MIXED-USE ZONE
MIX E D U S E C O MME RC IA L Z O N E The Kimihurura Sub Area is a Class A mixed use/commercial district, designed to visually and functionally anchor the whole Kimihurura Roundabout area, including the new Convention Center/Hotel and adjacent development. The Kimihurura Plan has been designed to create a place that both punctuates the area and produces a network of linkages to its surroundings. The urban complex serves as an iconic point of arrival in Kigali, and its height, massing and density guidelines suggest a high density sculptural urban quality with high peaks at the Roundabout stepping down to meet the development surrounding the site.Building functions,building configurations and lot occupations that help shape height and massing of the area are shown in Tables 12-14. In addition, Tables 12-14 show Site Planning Guidelines, including setbacks, building sitings and parking guidelines that work with the public rights-of-way to produce a vibrant street life and “outdoor living space,” and results in a network of surrounding open space. The goal of these guidelines is to work with the public circulation rights-of-way to assure that block and building development shapes the public and pedestrian spaces to create sustainable and socially attractive urban spaces. Please see Chapter 1 for more information and definitions on the terms in these tables.
MIXED-USE ZONES High Density Medium Density Neighborhood Center
0 0
200
m ft
800
From the perspective of sustainable urban design, building setbacks and façade design shall consider the role of the building within the assemblage in its block or plaza. The goal is to create public urban space between the buildings that is “larger and more interesting than the sum of its parts,” and that serves and excites the users. Building facades shall relate to adjacent and nearby buildings. They shall be articulated horizontally with detail so they do not appear massive, considering the pedestrian experience as a priority to sculptural quality.
Private developer block design shall link to adjacent public spaces and effort shall be made to ensure a well designed and varied public/private space network with no cut-offs or insecure cul-de-sacs. Large urban spaces shall be complimented with more intimate urban corridors, passageways and pocket parks within blocks. All block site design shall consider the broader “desire lines” for pedestrians, bikeways and autos, so that the block links pedestrian, bicycle, automobile and mass transit users to surrounding context. Pedestrian systems are designed to create a friendly environment for walkers, with welcoming, gentle walkways and plazas. Mass transit stops shall be considered in block design so that people have appropriate entry points and waiting areas. Parking entrances shall be secondary to alternative transportation services. Together, these elements shall reflect an interpretation of town life by creating true public spaces, where it is easy to be out of doors, to encounter friends, and in doing so, to build the community spirit. Site elements shall be designed together with buildings so that they are implemented together; and architectural budgets shall include site design buildout. Following, general Design Guidelines are outlined that reflect key considerations for sustainability and Rwanda appropriate design. Siting Considerations. Careful integration of buildings and other improvements with the natural landscape is critical to successful environmentally sensitive site planning, including Preserving and protecting existing and distinctive natural setting and ecosystems, responding to views and solar orientation, maintaining existing drainage patterns, minimizing grading and vegetation removal, and minimizing potentially adverse impacts to adjacent properties. Parking. In addition to parking shown on roadway rightsof-way, parking shall be located primarily on the interior of
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m Density
KIMIH U RU RA
TABLE 12:Mixed KIMIHURURA MIXED-USE Kinyinya Use High Density GUIDELINES
KI G A L I S U B A RE A P L A N N I N G
Zone T5-MU-HD A. BUILDING CONFIGURATION
T5
1. Building height shall be measured in number of stories, excluding attics and raised basements. 2. Stories may not exceed 4.25 m. in height from finished floor to finished ceiling, except for a first floor commercial function which must be a minumum of 3.3 m. with a maximum of 7.5m. 3. Height shall be measured to the eave or roof deck.
BUILDING FUNCTION Mixed Uses
permitted
Residential
permitted on upper floors
Lodging
limited use within overall structure
Office
permitted
Retail
permitted
Civic
permitted
Education (elementary)
permitted
BUILDING CONFIGURATION (See Table A) Principal Building
4 stories min. 10 stories max.w/stepped back penthouse
Outbuilding
not permitted
LOT OCCUPATION Lot Width
as per Sub Area Plan
Lot Coverage
60% min. 70% max.
"N" stands for any Stories above those shown, up to the maximum. Refer to metrics for exact minimums and maximums.
B1. SETBACKS - PRINCIPAL BLDG.
1. The facades and elevations of principal buildings shall be distanced from the lot lines as shown.
2. Facades shall be built along the principal frontage to the minimum specified width in the table.
BUILDING DISPOSITION Edgeyard
not permitted
Sideyard
permitted
Rearyard
permitted
Courtyard
permitted
SETBACKS - PRINCIPAL BUILDING (See Table B1) Front Setback Principal (g.1)
0-3 m. max.
Front Setback Secondary (g.2)
0-3 m. max.
Side Setback (g.3)
0-3 m. max.
Rear Setback (g.4)
0-3 m. max.
Frontage Buildout
80% min. at setback
B2. SETBACKS - OUTBUILDING 1. Outbuildings are prohibited in this zone.
SETBACKS - OUTBUILDING (See Table B2) setbacks are prohibited in this zone FRONTAGES Common Lawn
not permitted
Porch & Fence
not permitted
C.PARKING PLACEMENT
Terrace or Courtyard
permitted
1. Uncovered parking spaces may be
Forecourt
permitted
Stoop
not permitted
Shopfront & Awning
permitted
Gallery
permitted
Arcade
permitted
provided within the third layer as shown in the diagram
2. Covered parking shall be provided
within the third layer as shown in the diagram
PARKING PROVISIONS Commercial
1 space per 300 SM//10 bicycle spaces per 300 SM
Residential
1 space per 5 DU/1 bicycle parking space per DU.
3. Trash containers shall be stored
within the third layer.
blocks behind or under buildings. Urban blocks with a gradechange of one floor level or more provide an opportunity for covered parking garage space accessed from the lower side of the block. This configuration would allow the space above to be utilized for pedestrian plazas or terraces, where not directly under a building. Uncovered outdoor parking lots shall have a minimum of two canopy trees every 10-15 parking spaces for a minimum of 35% shade coverage of paving (after 5 years plant maturity) and shrubbed or groundcovered medians between parking bays. Servicing. All commercial uses must house materials and trash internally until pickup and all materials and garbage / recycling must be concealed from view. Transformers and other utility boxes will be located in landscape areas or set into sloped banks to partially conceal them from view. Planting shall be used to ease their visual presence. Utility connections and meters shall be incorporated into building or landscape walls for convenient access and minimal visual impact. Landscape Site Work. Landscape site materials, such as retaining walls, pedestrian pavements, steps and stairs, shall be complementary of the site’s unique setting, using Rwandan materials such as cobbles or granite block pavers if possible. These shall be standardized to create a unified and consistent “village” aesthetic, further re-enforcing the sense of place. • Walls shall maximize seating areas if possible. • For Paving: Stone or pre-cast concrete pavers are acceptable. Variations in pavers and patterns are encouraged in seating areas and patios outside the flow of pedestrian traffic to highlight different establishments. • Pedestrian walkways across curbs shall be handicapped accessible. • Steps, Stairs, Ramps shall be handicapped accessible and non-slip for safety and provide handrails supported by open railings or balusters rather than solid walls. They shall be designed as extensions of buildings and blend with adjacent pavement.
Street Furniture. Benches within the urban public space shall be amply provided for seating and walls shall be designed for seating. Kiosks and Information Boards. Shall be provided within public spaces, with protection from rain and appropriate dark sky lighting. Trash Receptacles shall be provided regularly on every block and shall be covered and consistently designed and labeled. Clearly labeled recycling receptacles shall be placed next to all large trash receptacles. Bicycle Racks. In general, bike racks within the urban public spaces shall be provided on every block and shall be of consistent design and provide a unifying site element, placed in easily accessible locations. Fencing may be used to control circulation, for safety protection, and to define edges of special areas. They shall not privatize the Kimihurura public space or cut it off from public access. They shall be similar in design to adjacent buildings and shall not restrict views except when concealing service areas.. All pool amenity areas are to be fenced. Signage. Signage shall follow a sign code developed to prevent the distraction of overstated displays of information and to establish a common visual character. Lighting. Detailed lighting designs shall be established for all of Kimihurura with the first construction project. In general, it shall provide safe and adequate illumination to allow for the movement of pedestrians and vehicles, shall facilitate nighttime activities, and contribute to overall ambiance within the area. Illumination levels shall be high enough to facilitate safety with a minimum of 10 lux on pedestrian surfaces, but not to create a bright, overly lit pedestrian environment.
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DEVE LOP ME NT & DESIGN GU IDEL INE S
Lighting shall be utilized as an overall compositional element linking various pedestrian corridors and distinguishing individual neighborhoods. Lighting shall strive to minimize energy consumption in all aspects of design. Light fixtures shall have a “cut off ” configuration to prevent light pollution into the night sky and beyond site boundaries. Light sources shall not produce more than 6 lux at site boundaries. Emphasis shall be placed on creating higher illumination levels at building entrances, stairs, ramps, major pedestrian spaces, decision points, etc. General lighting shall be from an LED, metal halide or high pressure sodium source and shall not overwhelm other secondary light sources used for retail display signage. Landscape Design. All new development shall prepare and present a landscape / revegetation plan which shall emphasize natural design, indigenous plant materials and revegetation of disturbed areas. Landscaping is encouraged to shade from the sun, cool hardscapes and provide beauty. • Landscape plantings are to define entries, design accents, and outdoor spaces; frame desirable views and vistas; buffer prevailing winds and provide color and/or shade. • Trees are to be selected for appropriate scale, canopy form, and durability. Shade trees with broad canopies above human standing height are encouraged. • Low spreading shrubs may be planted as understory to tree groupings, in particular in larger sized planting areas, on steeper slopes to control erosion, and on the outer perimeter. Ground level shall be covered by the most durable and low water plan materials available. • Perennial flowers or herbs shall be planted wherever possible within the urban center; and annual flowers shall be minimized to avoid excessive cost of replacement. • Lawn may be used in appropriate places such as for passive recreation, but shall be minimized in favor of perennial groundcover, low shrubs and native grasses where possible to preserve irrigation.
• •
• • •
Gray and harvested water shall be used where possible for irrigation. Trees or groups of trees adjacent to the construction area (especially heritage trees) shall be fenced and protected during the construction period. Trees and other existing vegetation are valued and are to be preserved whereever possible. Water conserving irrigation systems shall be installed where appropriate. Mulch all planting areas. Berms must appear to be a natural landform. They shall be compacted and have maximum slope of 2:1. Rocks that are uncovered during foundation excavation can be used very effectively to add visual interest by incorporating it into to the landscape design.
ME D IU M A N D L O W D E N SITY HO TE L ZONES Design Themes and Guiding Principles. Kimihurura Hotels will support the functions of the Conference Center, business community and provide a premier level of attraction to both residents of Rwanda and visitors. Each building design shall respect its place as part of the larger neighborhood community, and the City government may wish to consider the development of more refined design guidelines that ensure coherence in hotel design. While the unique character of each hotel is welcomed so that it may distinguish it from the others, hotel design shall be mindful the overall quality of the Sub Area, the layout of the hotel zone in a park-like setting,
FIGURE 60: KIMIHURURA HOTEL ZONES
and sensitivity to surrounding neighborhoods. The following development guidelines provide minimum requirements for the Kimihurura hotel zone. Professional Design Assistance. A high level of design quality will be expected at Kimihurura. It is required that all Owner/Developers engage a licensed architect familiar with the building types and who personally visits the site during the initial stages of the design review process. “Off the Shelf ” or stock plans are not acceptable design solutions. Environmental/Urban Sustainability shall be an integral part of development given a high level of attention. While unique designs are appreciated in the Kimihurura hotel district, hotel design shall be mindful of the following: • Integration with site; protection and preservation of site, trees, and surrounding natural environment • Minimize surface parking by providing underground parking for the majority of new development projects. • Wherever practical and economical, use environmentally friendly, native, and natural materials and sustainable design standards • Recycled materials be used where ever possible to make sustainable construction and maintenance a priority.
HOTEL ZONES High Density/Conference Center Medium Density Low Density (Eco-Tourism/Retirement Housing)
0 0
200
m ft
800
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KIMIH U RU RA KI G A L I S U B A RE A P L A N N I N G
TABLE 13: KIMIHURURA MIXED-USE GUIDELINES
Integration With The Hotel Park. A key element of these sites is their adjacency to the large park situated between them. This park is intended to provide a peaceful setting for walking, sitting and contemplation amidst a heavily tree’d setting. All development surrounding the park shall be mindful of this restful quality and hotel siting shall be designed accordingly. For example, hotel sites shall provide pedestrian orientation and access to the park, with transport and services accessing from behind. Roadways between hotels shall be ornamental, with heavier service access coming from the northern and southern ends of the hotel sites.
Kimihurura Hotel Medium Density
Kimihurura Hotel Low Density
Zone T2-H-MD
Zone T2-H-LD
T2
T2
T2
Development Guidelines for building function and configuration, lot occupation, building disposition, setbacks, frontages and parking are shown in Tables 12-14. Zoning standards shape the general regulations regarding layout, density, massing and Floor Area Ratio (FAR). These inlcude: • permitted building function and usage • building configuration (height/stories) • lot occupation (lot layout and coverage) • site building disposition, setbacks and frontages • parking provisions
BUILDING FUNCTION
BUILDING FUNCTION Residential
restricted use
Residential
restricted use
Hotel Medium Density
200-300 rooms
Hotel Low Density
100-200 rooms
Office
within hotel and conf. ctr.
Office
within hotel and conf. ctr.
Retail
within hotel
Retail
within hotel
BUILDING CONFIGURATION (See Table A)
Principal Building
4 stories max.
Principal Building
2 stories max.
Outbuilding
2 stories max.
Outbuilding
2 stories max.
LOT OCCUPATION Lot Width
20 m. min.
Lot Width
20 m. min.
Lot Coverage
60% max.
Lot Coverage
60% max.
Edgeyard
permitted
Edgeyard
permitted
Sideyard
permitted
Sideyard
permitted
Rearyard
permitted
Rearyard
permitted
Courtyard
permitted
Courtyard
permitted
SETBACKS - PRINCIPAL BUILDING (See Table B1)
SETBACKS - PRINCIPAL BUILDING (See Table B1)
Front Setback Principal (g.1)
7 m. min.
Front Setback Principal (g.1)
7 m. min.
Front Setback Secondary (g.2)
3.66 m. min
Front Setback Secondary (g.2)
3.66 m. min
Side Setback (g.3)
3.66 m. min
Side Setback (g.3)
3.66 m. min
Rear Setback (g.4)
3.66 m. min
Rear Setback (g.4)
3.66 m. min
Frontage Buildout
40% min. at setback
Frontage Buildout
40% min. at setback
SETBACKS - OUTBUILDING (See Table B2)
SETBACKS - OUTBUILDING (See Table B2)
Front Setback Principal (h.1)
6 m. min. + bldg. setback
Front Setback Principal (h.1)
6 m. min. + bldg. setback
Front Setback Secondary (h.2)
1 m. min. or 2 m. at corner
Front Setback Secondary (h.2)
1 m. min. or 2 m. at corner
Side Setback (h.3)
1 m. min.
Side Setback (h.3)
1 m. min.
1 The Facades and Elevations of Principal Buildings shall be distanced from the lot lines as shown. 2. Facades shall be built along the principal frontage to the minimum specified width in the table.
B2. SETBACKS - OUTBUILDING 1. The Elevations of the outbuilding shall be distanced from the Lot lines as shown.
C. PARKING PLACEMENT 1. Uncovered parking spaces may be
PRIVATE FRONTAGES
PRIVATE FRONTAGES permitted
Common Lawn
Porch & Fence
permitted
Porch & Fence
permitted
Terrace or Lightwell
not permitted
Terrace or Lightwell
not permitted
Forecourt
permitted
Forecourt
not permitted
Stoop
permitted
Stoop
permitted
Shopfront & Awning
permitted
Shopfront & Awning
not permitted
Gallery
permitted
Gallery
not permitted
Arcade
permitted
Arcade
not permitted
Hotel
B1. SETBACKS - PRINCIPAL BLDG.
BUILDING DISPOSITION
BUILDING DISPOSITION
Common Lawn
Height shall be measured to the eave or "N" stands for any Stories above those shown, up to the maximum. Refer to metrics for exact minimums and maximums. roof deck.
LOT OCCUPATION
permitted
provided within the second and third layer as shown in the diagram.
2. Covered parking shall be provided
within the third layer as shown in the diagram. Side- or rear-entry garages may be allowed in the first or second layer by warrant. 3. Service facilites and trash containers
PARKING PROVISIONS (See Table C)
PARKING PROVISIONS (See Table C)
Please see Chapter 1 for more information and definitions on the terms in these tables.
1. Building height shall be measured in number of Stories, excluding attics and raised basements. 2. Stories may not exceed 4.25 m. in height from finished floor to finished ceiling, except for a first floor commercial function which must be a minumum of 3.3m with a maximum of 7.5m.
BUILDING CONFIGURATION (See Table A)
Medium and Low Density Hotels. The hotel sites provide options for different types of hotel zones. In no case shall there be high density hotels of more than four stories and 300 rooms located in Kimihurura. Hotels of medium density/activity provide a more urbanized environment, with restaurants and shops, support conference/meeting rooms, spas and other facilities. Low density/activity hotels would be smaller, with a neighborhood bed and breakfast ambiance. These would not include a high level of amenity, opting for a more tranquil atmosphere. They would tend to have a more garden like setting.
A. BUILDING CONFIGURATION
.5 spaces per room plus 10% overflow Hotel and 10% employee
.5 spaces per room plus 10% overflow and 10% employee
.5 bicyicle space per employee
.5 bicyicle space per employee
shall be stored within the third layer.
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DEVE LOP ME NT & DESIGN GU IDEL INE S KIMIH U R U R A R ES ID ENT IA L Z O N E S The Kimihurura neighborhood center includes two residential zones: Residential Medium High (100 DU/Ha) and Residential Medium Low (70 DU/Ha) areas. Development Guidelines for building function and configuration, lot occupation, building disposition, setbacks, frontages and parking are shown in Table 14. Development guidelines that are unique to the Kimihurura residential site follow below. Please see Chapter 1 for more information and definitions on the terms in these tables. The neighborhood provides housing, commercial and community facilities for a variety of residents, including Rwandan residents who enjoy a more urban lifestyle, employees of government facilities located in the vicinity, as well as foreign visitor conducting business in Kigali, especially in the vicinity. The location makes it convenient for those who must travel extensively, with convenient access to the Kigali International Airport. In general, guidelines for basic principles of sustainable urbanist neighborhoods outlined in Chapter 2 will be appropriate for this area. While there are two different densities, the fundamental layouts and guidelines for the two zones are very similar, except that they will be different stories and will need to accommodate different parking.
•
•
•
•
Because the market population for this neighborhood is expected to be more short term, transient, or professionally oriented, the interior block landscaping is envisioned to be more low maintenance with urban agriculture tending towards fruit trees and ornamentals rather than subsistence or market gardens. For the same reasons, this area has a lower proportion of school children than more long term established neighborhoods; however, an Primary School is located to the southwest to accommodate children from this and surrounding neighborhoods. The Kimihurura Neighborhood Center is a moderate density area that includes primarily residential development. It is designed to promote the feeling of a “small town” community with easily walkable access to the commercial core, the conference center. The siting of this neighborhood follows the existing
neighborhood layout and every effort shall be made to respect existing heritage trees and cultural landscapes. Adjacent buildings shall reference each other with incremental sensitivity and attention to the spaces in between them so that the whole project reads as a community that evolves over time. Where site elements are closely related to the buildings, they may extend architectural design elements into the landscape, such as low walls, handrails, etc., which are direct extension of the building design.
A RC HITE C TU RA L S TA N D A RD S FO R A L L K IMIHU RU RA B U IL D IN GS All buildings should be sited and designed to take advantage of the local climate for optimum sustainability in cooling and air quality. This includes orientation and design features that incorporate sun/shade factors and wind/breezes. Buildings
FIGURE 61: KIMIHURURA RESIDENTIAL ZONES
Residential blocks have been designed to support sustainable urbanist objectives outlined in Chapter 2.1 Blocks are laid out along the traditional lanes from the former military base already found on the site, with buildings close to the setbacks so that streets are “living” and peoples’ “eyes are on the street” for safety and security. Pedestrian and bicycle traffic are maximized while automobile traffic is minimized. The Kimihurura Residential Zones diverge slightly from the Standard Zone configuration found in Rebero or Kinyinya for several reasons. • Because there is such a high proportion of retail in the mixed-use commercial center, neighborhood community centers and retail would be limited in this zone to groceries, small shops selling necessities, and pharmacies.
RESIDENTIAL ZONES High Density Medium-High Density Medium-Low Density
0
1
Single family housing Housing Guidelines were outside the scope of this project.
0
200
m ft
800
should generally be oriented along an east/west axis, or configured to reduce low east morning and low west afternoon sun exposure on facades and into windows. Building Roofs. Roofs may be pitched or flat. Flat roofs shall be constructed with a waterproof membrane that slopes a minimum of two percent (2%) to drain. Roof tiles or shingles shall not be used on pitches less than 25%. • Rainwater Harvesting. All roofs must be capable of accommodating the catchment and collection of rain water for other use. At a minimum, rainwater shall be controlled and released into open storm drainage systems. Use in landscape irrigation is encouraged. Storage of rainwater for use in “gray” water systems, such as waste removal, will lighten the demand on potable water distribution. • Green Roof Gardens. Flat roofs shall be capable of accommodating the growth of live plant materials on these surfaces. • Solar Photovoltaic (PV) Panels Or Films. Roofs shall be capable of accommodating solar pv panels or films for the generation of electricity. On large flat roofed buildings, these may be placed on the roof of the highest (penthouse) level flat horizontally to the sky or as a translucent canopy over a green roof. • Water Storage Tanks. Roofs of buildings over four stories shall be structurally capable of supporting water storage for gravity feed gray water and fire extinguishing systems. • Deep overhangs are generally recommended for shading and weather protection of wall surfaces. • Roof surfaces shall be light in color to avoid heat absorption and creation of heat islands. • Rooftop accoutrements and equipment (including such items as mechanical units, vents, satellite dishes and antennae) shall be either integrated into the design, concealed from view or painted to reduce the visual impact. • Note: the commitment to installing green roofs, solar pv and water storage tanks at initial construction is not required. The initial design and construction should be capable of adding these features in the future, if not initially installed, without major structural modification. Exterior Façade/Walls. Large building facades and massing should step down from the massive to the personal/ pedestrian scale. Building extensions, such as covered entries, porches, overhangs and/or arcades are used to add texture to buildings,
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KIMIH U RU RA
TABLE 14: KIMIHURURA RESIDENTIAL GUIDELINES
KI G A L I S U B A RE A P L A N N I N G
Kimihurura Residential-Med.Low Density
Kimihurura Residential-Med. High Density
Zone T4-R-MLD
Zone T4-R-MHD
T4
T4
A. BUILDING CONFIGURATION 1. Building height shall be measured in number of Stories, excluding attics and raised basements.
2. Stories may not exceed 4.25 m. in height from finished floor to finished ceiling, except for a first floor commercial function which must be a minumum of 3.3m with a maximum of 7.5m. BUILDING FUNCTION Residential
BUILDING FUNCTION open
Residential
Community Center w/in neighborhood block
open
Community Center w/in neighborhood block
open
Lodging
limited use: guest houses and Bed and Breakfast
Lodging
limited use: guest houses and Bed and Breakfast
Office
limited use encouraged for neighborhood office
Office
limited use encouraged for neighborhood office
Retail
limited use encouraged for neighborhood retail
Retail
limited use encouraged for neighborhood retail
open
BUILDING CONFIGURATION (See Table A)
BUILDING CONFIGURATION (See Table A) Principal Building
4 stories max/2 stories min. av. 2Principal Building 3 stories
6 stories max.w/stepped back penthouse
Outbuilding
2 stories max.
2 stories max.
LOT OCCUPATION
Outbuilding
by block per Sub Area Plan
Lot Width
by block per Sub Area Plan
Lot Coverage
60% min. 70% max.
Lot Coverage
60% min. 70% max.
BUILDING DISPOSITION
1 The facades and elevations of principal buildings shall be distanced from the lot lines as shown. 2. Facades shall be built along the principal frontage to the minimum specified width in the table.
not permitted
Edgeyard
not permitted
Sideyard
permitted
Sideyard
permitted
Rearyard
permitted
Rearyard
permitted
Courtyard
permitted
Courtyard
permitted
SETBACKS - PRINCIPAL BUILDING (See Table B1)
SETBACKS - PRINCIPAL BUILDING (See Table B1)
Front Setback Principal (g.1)
0 m. min., 4 m. max.
Front Setback Principal (g.1)
0 m. min., 4 m. max.
Front Setback Secondary (g.2)
0 m. min., 4 m. max.
Front Setback Secondary (g.2)
0 m. min., 4 m. max.
Side Setback (g.3)
0 m. min., 4 m. max.
Side Setback (g.3)
0 m. min., 4 m. max.
Rear Setback (g.4)
0 m. min., 4 m. max.
Rear Setback (g.4)
0 m. min., 4 m. max.
Frontage Buildout
60% min. at setback
Frontage Buildout
60% min. at setback
6 m. min. + bldg. setback
Front Setback Principal (h.1)
6 m. min. + bldg. setback
Front Setback Secondary (h.2)
0 m. min. or 1m. at corner
Front Setback Secondary (h.2)
1 m. min. or 2 m. at corner
Side Setback (h.3)
1 m. min.
Side Setback (h.3)
1 m. min.
SETBACKS - OUTBUILDING (See Table B2)
SETBACKS - OUTBUILDING (See Table B2)
Common Lawn
permitted
Common Lawn
Porch & Fence
permitted
Porch & Fence
limited
Terrace or Lightwell
permitted
Terrace or Lightwell
permitted
Forecourt
permitted
Forecourt
permitted
Stoop
permitted
Stoop
limited
Shopfront & Awning
permitted
Shopfront & Awning
permitted
Gallery
permitted
Gallery
permitted
Arcade
permitted
Arcade
permitted
permitted
"N" stands for any Stories above those shown, up to the maximum. Refer to metrics for exact minimums and maximums.
Building Systems. Cooling shall be implemented by natural ventilation, shading, building configuration and other passive means as is optimal. The use of radiant barriers, insulation, vented skin and low emissivity glass in the building envelop will reduce the demand of day time heat gain. Night time flushing of air can cool the interior thermal mass. Supplementary ventilation and cooling, if necessary, shall be designed to minimize energy use. Strategies must take advantage of variable demand and diversity of use. Alternatives to high electrical demand direct expansion air conditioning (DX) systems such as: evaporative cooling during dry seasons, geothermal heat exchange with release of heat in ground coils or subsurface water, domestic water cooling of the structure in perimeter chill beams and in floor “radiant” cooling shall be considered. Day-lighting. Day-lighting shall be optimized to reduce building electrical demand. Strategies such as: high windows and ceilings, clerestories above light shelves, exterior light reflective surfaces, perimeter reflective louvers, interior transoms, borrowed light windows, skylights, sunlight tubes will enhance the penetration of natural light deep into the interior of the structure. Efficient artificial light fixtures such as direct/indirect pendants for office space and fixtures with reflective housings and diffuse lenses with LED, T8, T5 or compact fluorescent lamps will maximize the lumens per watt of electricity.
C. PARKING PLACEMENT 1. Uncovered parking spaces may be
provided within the second and third layer as shown in the diagram. 2. Covered parking shall be provided within
FRONTAGES
FRONTAGES
B2. SETBACKS - OUTBUILDING 1. The elevations of the outbuilding shall be distanced from the lot lines as shown.
BUILDING DISPOSITION
Edgeyard
the third layer as shown in the diagram. Side- or rear-entry garages may be allowed in the first or second layer by warrant. 3. Service facilites and trash containers shall
be stored within the third layer.
Seismic/Earthquake Protection. Because of significant seismic activity, an epicenter in the Albertine Rift Zone and recent tectonic activity in the Virunga Mountains, all construction in Rwanda must comply to building codes which specify resistance to earthquakes in order to protect human life and safety. As of 2006, KIST accepted a peak ground acceleration coefficient of 0.27gh ; also, short period Ss design spectral response of 1.24 and one second S1 design spectral responses of 0.56 were reported in a US Army Corps of Engineers technical memorandum in 2002). Seismic design criteria shall be updated, then applied to all new construction. It is recommended that all construction follow life safety codes for structural live, dead and wind loads as well as fire.
PARKING PROVISIONS (See Table C)
PARKING PROVISIONS (See Table C) Residential
B1. SETBACKS - PRINCIPAL BLDG.
LOT OCCUPATION
Lot Width
Front Setback Principal (h.1)
3. Height shall be measured to the eave or roof deck.
to provide a connection to the outdoors, and bring large buildings down to a pedestrian scale. These extensions are also important factors contributing to energy efficiency by providing shading and breaking up the building envelope. • Overhangs, sunshades, light shelves, awnings and living “green” walls are encouraged for use in keeping the building cool. Large areas of un-shaded glass shall be avoided. Glass curtain walls shall be placed in predominately shaded areas or be equipped with integral shading devices. • Building wall surfaces (other than glass, solar walls, living “green” walls, native stone, brick and accent walls) shall be generally light in color, capable of reflecting at least thirty five percent (35%) of the daylight striking them.
2 parking spaces per 5 units 1 bicycle space per unit
Residential
2 parking spaces per 5 units 1 bicycle space per unit
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MUN ICIPAL FINANC ING This chapter addresses the Capital Improvement Plan and Municipal Financing strategies for development of the Kimihurura site and includes a phasing plan and payment/ municipal financing recommendations for implementation of the proposed plan outlined in previous chapters.
PHA SIN G PLA N The phasing plan has been synchronized across all infrastructure systems to best accommodate various factors, including infrastructure engineering considerations, typical real estate development patterns, marketing strategies, and expropriation, and residential needs. Phasing should be adjusted only with guidance from engineers and designers because any major modification will change the infrastructure required to be constructed as a result of the adjustment. This will not only affect the scope of work to be completed but could increase the costs associated with that phase as well as the overall project cost. The Kimihurura sub area is an existing city center with a strong government and military presence. The phasing plan has been synchronized across all infrastructure systems to best accommodate various factors, including infrastructure engineering considerations, typical real estate development patterns, marketing strategies, and expropriation and residential needs. As shown in Figure 62, there are 4 phases to the Kimihurura plan. Phase 1 allows for the development of the hotel and convention center, the mixed use high density areas, the plaza and promenade, the central areas of medium-high density residential and medium density hotels. • Major infrastructure associated with the first phase includes the construction of: 1. The water system including additional storage, offsite transmission line, a portion of the on-site main transmission line, and approximately ¾ of the distribution lines and the associated service lines. 5-36 KIGALI S UB AREA PLANN IN G
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2. The wastewater system including the temporary mechanical plant, the main collection line, the associated service lines, and ½ of the minor collection lines. 3. The electrical system including the main transmission line and ½ of the distribution lines and the associated service lines. 4. The road system including the major arterial roadway running north-south, the major collector around the convention center, and a portion of the connecting collector and local roadways. 5. The drainage system including the ETZ with constructed wetlands, storm drainage pipes around the convention center major collector roadway, bioretention water dissipation areas, and aesthetic storage pond.
PHASE I
Phase 2 allows for the development of the school, the low density hotels, and the remaining residential areas. • Major infrastructure associated with the second phase includes the construction of: 1. The water system including a portion of the main transmission line and ¼ of the distribution lines and associated service lines. 2. The wastewater system including ¼ of the minor collection lines and associated service lines. 3. The electrical system including ½ of the distribution lines and associated service lines. 4. The road system including a portion of the collector and local roads in the southwest area of the site. 5. The drainage system including a portion of the major drainage swale and sedimentation basin.
PHASE III PHASE II
PHASE IV
PHASE IV
LEGEND ELECTRIC 200MM HIGH PRESSURE WATERLINE 250MM HIGH PRESSURE WATERLINE 200MM SANITARY SEWER 250MM SANITARY SEWER
N
FIGURE 62: PHASING MAP
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K I M I H U R U R A KI G A L I S U B A RE A P L A N N I N G
• •
Phase 3 allows for the development of the remaining hotels and adjacent park south of the convention center. Major infrastructure associated with the third phase includes the construction of: 1. The water system including service lines to the hotel area. 2. The wastewater system including ¼ of the collection lines, located along the eastern most collection road. 3. The electrical system including service lines to the hotel area. 4. The road system including the north-south collection road along the eastern boundary of the site. 5. The drainage system including a portion of the major drainage swale.
Phase 4 allows for the development of the east-west arterial roadway south of the site. Although described here, Phase 4 is not included in the cost and revenue analysis in this chapter. Major infrastructure associated with the first phase includes only the construction of the major east-west arterial roadway system. Development Program. Table 15 details the development plan for Kimihurura, by development type and by phase. The phasing plan below is coordinated with the infrastructure phasing plan to both minimize initial costs and maximize development potential. Although some infrastructure has been delayed to Phase III, all of the development is completed by the end of Phase II. TABLE 15: DEVELOPMENT PROGRAM Type
Phase I
Phase II
Phase III
Total Units
Total Sq. Meters
Residential (units) Medium-Low Density Medium-High Density High Density Total Non-Residential (square meters) Hotel Conference Center Community Commercial Total
143 434 120 697
143
143
0
39,273 180,000 45,000 264,273
28,364
14,182
28,364
14,182
286 434 120 840
1,500
M UN I C IPA L FIN A N C IN G Summary of Analysis For Kimihurura, the planning team has prepared an estimate of the cost of infrastructure required to support the proposed plan. As has been discussed in the Chapter Three general introduction to infrastructure finance, it is our opinion that development should pay for both the project level and municipal infrastructure needs it creates. In this spirit, the following chapter provides an example of how the municipal infrastructure cost responsibilities for Kimihurura could be distributed among the planned development. The overall cost allocation can be met in a number of ways, as will be elaborated later in this chapter. Simply put, it comes down having the City of Kigali pay for the costs of infrastructure “up front,” with a reimbursement made by the developer through various mechanisms. For the City’s upfront costs, there are two options: cash payment or financing. If a cash payment is made, this would come from a government/ministerial budget from a variety of sources such as government funds, general taxes, donor contributions, etc. If the City finances its expenditures, funding could come through bonds, donor lending (including bilateral, multilateral, development banks etc.), or private lending. If costs are financed, there will be additional costs of interest which makes the cost higher in the end.
The remainder of this chapter walks through the process of calculating what the fair share should be for each development type. • The first step in calculating the proper allocation of costs is the creation of an infrastructure plan. This step is shown in the previous parts of this section. • Second, cost estimates are made for the infrastructure plan, and this is shown below in Table 16: Summary of Results. • Third, the analysis determines a cost allocation methodology to each type of infrastructure improvement. • Fourth, this allocation methodology is applied to each type of development to determine the fair share of infrastructure costs to be applied to that development type. • Lastly, the fair share allocation is calculated on a per unit or per square meter basis and integrated with the development program to generate a phased infrastructure revenue plan. This, combined with the phased infrastructure costs, is the infrastructure financing plan. TABLE 16: SUMMARY OF RESULTS
Category
Estimated Fair Share Infrastructure Cost (RwF)
(USD)
Units/ Square Meters
Per Unit/Sq. Meter (RWF)
Financed Annual Cost (RwF)1 (USD) USD
Residential (per unit)
Regardless of how upfront costs are paid for by the Rwanda/Kigali government, it is recommended that they are reimbursed by real estate developers. But this reimbursement must be shared by developers fairly according to transparent formulas. This analysis presents a clearly laid out approach to dividing up the costs by type of use, based on a dwelling unit or per square meter rate. Table x provides a summary of that analysis, with a cost per unit or square meter, as appropriate. It shows the cost in the left hand column. Assuming the cost is financed and paid back over 20 years at an average 9 percent interest, the annual debt service is indicated in right hand column in the table below.
Med-Low Density Med-High Density High Density
3,358,097 4,888,460 1,282,112
286 434 120
Commercial (per Square Meter) Hotel 3,084,615,004 5,411,605 Office 6,774,862,550 11,885,724 Retail 2,275,615,534 3,992,308
81,818 180,000 45,000
1
1,914,115,082 2,786,421,983 730,803,850
6,692,710 11,742 6,420,327 11,264 6,090,032 10,684
37,701 37,638 50,569
66.14 66.03 88.72
733,163 1,286 703,324 1,234 667,142 1,170
4,130 4,123 5,540
7.25 7.23 9.72
Assumes financing at an interest rate of nine percent annually and a term of 20 years.
Sources: Oz Architecture, Tetratech, City of Kigali, AECOM
81,818 180,000 45,000 306,818
Sources: Tetratech, AECOM
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MUN ICIPAL FINANC ING Infrastructure Costs Table 17, below, provides a summary of the estimated improvement costs for the Kimihurura plan. As shown in the table, the total costs are estimated at 17.6 billion RwF, or approximately $30.8 million USD. The majority of these costs are in paths/trails, road, and shallow utility improvements. Table 18, below, provides a breakdown of infrastructure costs by phase. As can be seen in the table, the lion’s share of infrastructure costs, RwF 13.5 billion, or $23.7 million USD, occur early on, but significant costs are delayed to the third phase. To assist with financial feasibility, the infrastructure plan has been phased to minimize upfront costs to the greatest extent possible in order limit the initial capital requirements
of implementing the development plan. The third phase is largely unnecessary for development of Kimihurura but rather consists largely of road improvements that benefit city and district-level transportation.
costs are allocated by water demand for each development type. For each allocation methodology the table calculates a percentage distribution, which is applied to the infrastructure costs as described in Table 20.
Cost Allocation Methodology Once the capital improvement program is determined, the next step is to determine the allocation of costs across development types in a methodology that assigns a fair share burden for each. Table 19, below, summarizes the allocation of infrastructure costs among the development types. Each type of infrastructure is allocated according to a specific methodology. Road costs are allocated by vehicular trip generation, for example, while water and sewer
Using the percentage allocations from Table 18, Table 19, calculates the fair share burden of infrastructure costs for each infrastructure type and allocates it to the proposed development. The total allocated infrastructure costs for each development type is in turn divided by the number of units or square feet for that development type to arrive at an average burden, labeled “Total Cost per Unit/SqM” in Table 20. In the case of the medium-low density residential units, for example, the total infrastructure
TABLE 17: SUMMARY OF IMPROVEMENT COSTS New BIP Costs 2009 (RwF)
Item
Grading Drainage Water System Wastewater Shallow Utilities Roads Landscaping Paths/Trails Admin. Costs Total Cost
TABLE 19: COST ALLOCATION FACTORS Cost Allocation Factors Kimihurura Conceptual Infrastructure Financing Plan
(USD)
808,151,000 312,804,600 1,963,601,822 912,365,725 2,951,810,340 4,433,784,980 250,110,568 5,759,879,880 173,925,089
1,417,809 548,780 3,444,915 1,600,642 5,178,615 7,778,570 438,790 10,105,052 305,132
17,566,434,003
30,818,305
Potential Allocation Methodology [1]
TABLE 18: Conceptual SUMMARYInfrastructure OF IMPROVEMENTS AND COSTS BY PHASE OF DEVELOPMENT Kimihurura Financing Plan
Item Phase I (RwF)
(USD)
Estimated Costs By Improvement and Phase Phase II (USD) Phase III (USD)
Total (RwF)
(USD)
%
Total Costs Grading Drainage Water System Wastewater Shallow Utilities Roads Landscaping Paths/Trails Admin. Costs Total % of total
600,872,240 196,144,000 1,625,049,239 829,068,925 2,518,785,545 3,504,870,640 142,344,298 3,936,640,440 133,537,753
1,054,162 344,112 2,850,964 1,454,507 4,418,922 6,148,896 249,727 6,906,387 234,277
135,292,670 237,356 101,037,850 177,259 301,435,585 528,834 58,016,925 101,784 418,213,600 733,708 781,003,640 1,370,182 92,531,070 162,335 1,617,141,040 2,837,090 35,046,724 61,485
71,986,090 15,622,750 37,116,998 25,279,875 14,811,195 147,910,700 15,235,200 206,098,400 5,340,612
126,291 27,408 65,118 44,351 25,985 259,492 26,728 361,576 9,369
13,487,313,080 77%
23,661,953
3,539,719,104 6,210,034 20%
539,401,820 3%
946,319
808,151,000 312,804,600 1,963,601,822 912,365,725 2,951,810,340 4,433,784,980 250,110,568 5,759,879,880 173,925,089
1,417,809 548,780 3,444,915 1,600,642 5,178,615 7,778,570 438,790 10,105,052 305,132
17,566,434,003 30,818,305 100%
5% 2% 11% 5% 17% 25% 1% 33% 1%
Future Developed Hectares Total Developed Hectares % Distribution Dwelling Units and Square Meters Dwelling Units % Distribution Commercial Square Meters % Distribution Square Meters per DU Sewer/Water DUEs DUEs per Unit or SqM of Space Total DUEs % Distribution Storm Drainage DUEs DUEs per unit or per acre Total DUEs % Distribution Trip Generation Trip DUEs New PM Trips % Distribution Demographic Characteristics Persons per household New Population % Distribution Employment: SqM per employee New Employees % Distribution Daytime Population [2] New Daytime Population % Distribution
Totals
28.5 100%
Residential Low/Open Density
0
Low Density
0.0
840 100% 306,818 100% 2,000
2,228 100%
1.00 0 0.0%
7,367 100%
2.72
Residential Uses Medium Density
High Density
2.5 8.6%
3.1 10.9%
1.0 3.5%
286 34.0%
434 51.7%
120 14.3%
Office
Retail
8.0 27.9%
11.0 38.5%
3.0 10.5%
81,818 26.7%
180,000 58.7%
45,000 14.7%
130
130
0.00 0
1.00 286 12.8%
1.00 434 19.5%
1.00 120 5.4%
3.67 938 42.1%
0.64 360 16.2%
0.64 90 4.0%
0.00 0 0.0%
1.00 286 3.9%
1.46 635 8.6%
1.94 233 3.2%
239.36 1,905 25.9%
307.75 3,385 46.0%
307.75 923 12.5%
1.40
1.25 358 7.5%
1.00 434 9.1%
0.70 84 1.8%
1.00 900 19.0%
1.00 1,980 41.7%
2.00 990 20.9%
4.00
4.00 1,144 34.0%
4.00 1,736 51.7%
4.00 480 14.3% 55 1,500 13.2%
23 7,920 69.5%
23 1,980 17.4%
750 8.3%
3,960 43.7%
990 10.9%
11,400 100% 9,060 100%
Hotel
130
4,746 100%
3,360 100%
Med-Low Residential
1,144 12.6%
1,736 19.2%
480 5.3%
[1] The 'Allocation Factor' column in the follow ing table indicates w hich of these factors have been applied to allocate each category of costs. [2] Daytime population is defined as population plus half of the employment. This is intended to reflect low er impacts on service costs by employees than by residents
Sources: Tetratech, AECOM
Sources: Tetratech; AECOM
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K I M I H U R U R A KI G A L I S U B A RE A P L A N N I N G
costs are RwF 1.9 billion. This total is divided by the number of medium-low density residential units in the Kimihurura plan, 286, to arrive at an allocated responsibility per unit of approximately RwF 6.7 million per unit.
TABLE 20: SUMMARY OF BIP COSTS AND AREA DEVELOPMENT COST BURDENS
Facility
Developer BIP Costs Grading Drainage Water System Wastewater Shallow Utilities Roads Landscaping Paths/Trails Administration Costs (2) TOTAL BIP COSTS Area Development Impact Fee Burdens Total Cost per Unit/SqM Average Market Values Costs as Percent of Value
Total BIP Costs (RwF)
808,151,000 312,804,600 1,963,601,822 912,365,725 2,951,810,340 4,433,784,980 250,110,568 5,759,879,880 173,925,089
Allocation Factor Utilized (1)
Non-residential Uses Med-Low Residential
Trips Impermeable Surface Water Demand Water Demand Daytime Pop. Trips Trips Daytime Pop. 1% of costs
17,566,434,003
Medium Density
High Density
Hotel
Office
Retail
60,881,674 12,143,523 252,116,777 117,143,254 372,723,072 334,017,096 18,841,961 727,296,091 18,951,634
73,909,500 26,952,697 382,582,802 177,762,839 565,600,745 405,492,083 22,873,878 1,103,659,103 27,588,336
14,305,065 9,872,783 105,783,263 49,151,015 156,387,303 78,482,339 4,427,202 305,159,199 7,235,682
153,268,549 80,898,743 826,431,743 383,992,309 244,355,161 840,882,200 47,434,308 476,811,248 30,540,743
337,190,808 143,736,101 317,349,789 147,453,046 1,290,195,248 1,849,940,841 104,355,479 2,517,563,391 67,077,847
168,595,404 39,200,755 79,337,447 36,863,262 322,548,812 924,970,420 52,177,739 629,390,848 22,530,847
1,914,115,082
2,786,421,983
730,803,850
3,084,615,004
6,774,862,550
2,275,615,534
na
na
RWF 6,692,710
RWF 6,420,327
RWF 6,090,032
RWF 37,701
RWF 37,638
RWF 50,569
na na
na na
RWF 65,000,000 10.3%
RWF 60,000,000 10.7%
RWF 55,000,000 11.1%
RWF 605,000 6.2%
RWF 605,000 6.2%
RWF 605,000 8.4%
(1) This column indicates w hich allocation factor is used to allocate each cost item; see table prior for allocation formulas. (2) Administrative Costs are assumed to be one percent of infrastructure and public facilities costs.
Kimihurura ConceptualOF Infrastructure Plan TABLE 21: SUMMARY BIP COSTSFinancing AND AREA DEVELOPMENT COST BURDENS, OPTION A
Facility
Developer BIP Costs Grading Drainage Water System Wastewater Shallow Utilities Roads Landscaping Paths/Trails Administration Costs (2) TOTAL BIP COSTS Area Development Impact Fee Burdens Total Cost per Unit/SqM Average Market Values Costs as Percent of Value
Total BIP Costs (RwF)
808,151,000 312,804,600 1,963,601,822 912,365,725 2,951,810,340 4,433,784,980 250,110,568 5,759,879,880 173,925,089
Allocation Factor Utilized (1)
Non-residential Uses Med-Low Residential
Trips Impermeable Surface Water Demand Water Demand Daytime Pop. Trips Trips Daytime Pop. 1% of costs
17,566,434,003
Medium Density
High Density
Hotel
Office
Retail
43,247,359 12,143,523 414,905,465 192,781,205 283,656,334 237,269,386 13,384,407 553,499,792 17,508,875
52,501,689 26,952,697 255,055,201 118,508,560 430,131,557 288,041,716 16,248,482 839,317,509 20,267,574
10,161,617 9,872,783 70,522,175 32,767,344 118,964,648 55,750,009 3,144,868 232,136,217 5,333,197
163,311,706 80,898,743 826,431,743 383,992,309 278,823,395 895,982,295 50,542,514 544,069,258 32,240,520
359,285,753 143,736,101 317,349,789 147,453,046 1,472,187,525 1,971,161,049 111,193,531 2,872,685,683 73,950,525
179,642,876 39,200,755 79,337,447 36,863,262 368,046,881 985,580,525 55,596,766 718,171,421 24,624,399
1,768,396,345
2,047,024,985
538,652,858
3,256,292,482
7,469,003,002
2,487,064,332
na
na
RWF 9,274,806
RWF 7,074,971
RWF 6,733,161
RWF 39,799
RWF 41,494
RWF 55,268
na na
na na
RWF 65,000,000 14.3%
RWF 60,000,000 11.8%
RWF 55,000,000 12.2%
RWF 605,000 6.6%
RWF 605,000 6.9%
RWF 605,000 9.1%
In order to understand the effect on development feasibility of imposing this cost burden, Table 20 also compares the cost burden to the likely market value of the units in question. In the case of residential units, we assume that the units will sell for between RwF 55 million ($96,000 USD) and RwF 65 million ($113,000 USD) each. The calculated development burden for the residential types is from ten to eleven percent. As a rule of thumb, infrastructure burdens should not exceed ten percent of total development value (and the lower it is, the lower the effect on feasibility), so the burden calculated for residential development in Kimihurura appears just above the level of feasibility. This analysis does not contemplate the implementation of affordable housing. The analysis puts the entire burden of infrastructure on market-rate housing and commercial development and assumes that affordable housing (as well as schools and other public facilities) do not contribute. Any allocation of infrastructure burden would either reduce affordability or increase the subsidy necessary to maintain affordability. The general analysis in this chapter does not incorporate assumptions about affordable housing, but affordable housing in Kimihurura may be as high as one third of total units, as recommended by the Sub Area Plan and the Kigali Conceptual Master Plan approach to mixed standings. If affordable housing is envisioned, then the formula would change, so that the analysis puts the entire burden of infrastructure on market-rate housing and commercial development and assumes that affordable housing (as well as schools and other public facilities) do not contribute. This is because any allocation of infrastructure burden to affordable housing would either reduce affordability or increase the subsidy necessary to maintain affordability. In Table 21: Summary of BIP Costs and Area Development Cost Burdens, Option A, 1/3 of the housing is removed from the residential infrastructure burden. In this case, market rate development will bear a higher burden of the costs. However, the tangible and intangible benefits of incorporating affordable housing must be part of a broader evaluation of feasibility and long term sustainable development.
(1) This column indicates w hich allocation factor is used to allocate each cost item; see table prior for allocation formulas. (2) Administrative Costs are assumed to be one percent of infrastructure and public facilities costs. Sources: Tetratech; AECOM
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MUN ICIPAL FINANC ING Infrastructure Financing Plan Ideally, the income from development fees would be available before municipal infrastructure was built, but this is not so. Infrastructure is usually built prior to private sector investors and developers come “on board,� and it is often the incentive that attracts them to overcome risk and build in an area. Therefore, the City must evaluate the financial picture over time to see how and when development fees will start to accrue and to assess how much it will need to finance in the interim. The next step in the Financing Plan is to examine the balance of costs and revenues accruing to determine the shortfall between them, and the extent to which supplemental funding will be necessary to cover temporary shortfalls. Shortfalls can be long-term or short-term and ultimately the method used to cover them will be determined by their duration, among other factors. This analysis is done by assessing the comparative patterns of revenue expenses and income over time. Costs are assessed over time in Tables 20 and 21. To balance out the analysis, an assessment of revenues is required; and Table 22 calculates the fee revenue that will accrue to the financing plan from the development of Kimihurura.
Typically, many of the larger infrastructure costs are up front, before sufficient development occurs to cover its costs. The gap between expenses and income can be derived by comparing them in a table that shows a cash flow analysis, as in Table 23: Cost and Revenue Phasing. Using the impact fee revenue in Table 22 and the cost allocations in Table 19, Table 23, calculates the infrastructure finance cash flow for the table below combines the revenue calculated in the table directly above and the infrastructure costs detailed earlier in this chapter to calculate an infrastructure financing cash flow for the Kimihurura plan. As shown on Table 23 below there is a surplus of RwF 1.5 billion as the Phase I infrastructure required is less than the fair share cost allocation for the Phase I development. This is unusual for infrastructure financing plans, and it provides a cushion of funding for later phases. Next Steps The calculation of the infrastructure burdens is only the first step in developing an infrastructure financing plan. It provides an overview of the relationship of each development type to the infrastructure required to implement the plan. This information also allows for a discussion of the infrastructure burden created by each type of development and the ability of that development to bear its fair share. To
Phase I (RwF)
Residential (units) Med-Low Density 951,570,258 Medium-High Density 2,783,779,505 High Density 725,492,620 Total 4,460,842,384
(USD)
Phased Revenue Phase II (RwF) (USD) Phase III (RwF)
(USD)
Total (RwF)
1,669,422 4,883,824 1,272,794 7,826,039
951,570,258 0 0 951,570,258
1,669,422 0 0 1,669,422
0 0 0 0
0 0 0 0
Non-Residential (square meters) Hotel 1,483,401,070 2,602,458 Office 6,785,174,563 11,903,815 Retail 2,278,427,901 3,997,242 Total 10,547,003,535 18,503,515
1,071,345,217 0 0 1,071,345,217
1,879,553 0 0 1,879,553
535,672,609 0 0 535,672,609
939,777 0 0 939,777
1,903,140,517 2,783,779,505 725,492,620 5,412,412,643
For example, the City can allow for financing of the fee that would allow for smaller annual payments to cover the infrastructure costs allocated to each development type. In addition, the City can waive part or the entire infrastructure burden to encourage particular types of development or particular projects. It is important to note, however, that where the burden is waived the City will have to come up with alternate financing to cover the costs. Conventional development should not typically receive subsidies without a compelling policy justification. The issue of variance to the standard development fee assessment is a policy question that must be decided after considered analysis and transparent public discussion. The point of these calculations is to provide an example of how infrastructure costs can be allocated and what the general burdens might be for each development type. By understanding the details and timing of its infrastructure burden, the City can make judicious choices about how to proceed with its expenditures. Separately the government must decide how to structure the financing mechanisms that pay for these investments. A more detailed discussion of the options is contained in Chapter Three.
p g TABLE 22: INFRASTRUCTURE FEE REVENUE
Type
the extent development cannot support its fair-share burden, for example, because it includes affordable housing or community facilities, the City can either assist or make adjustments to the development program to aid in the feasibility of the plan. Adjustment scenarios are discussed in Chapter Three, Municipal Financing and in Appendix 1: Making Housing More Affordable.
(USD)
3,338,843 4,883,824 1,272,794 9,495,461
3,090,418,896 5,421,788 6,785,174,563 11,903,815 2,278,427,901 3,997,242 12,154,021,361 21,322,844
TABLE 23: COST AND REVENUEFinancing PHASING Kimihurura Conceptual Infrastructure Plan Item
Phase I (RwF)
Revenues
15,007,845,919
Costs Net
(USD)
Phase II (RwF)
USD
26,329,554
2,022,915,476
3,548,975
535,672,609
13,487,313,080
23,661,953
3,539,719,104
6,210,034
539,401,820
1,520,532,839
2,667,601
(1,516,803,628) (2,661,059)
Phase III (RwF)
(3,729,211)
(USD)
Total (RwF)
(USD)
939,777
17,566,434,003
30,818,305
946,319
17,566,434,003
30,818,305
0
0
(6,542)
Sources: Tetratech, AECOM
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