The New Piura
The functional vision and mission of a less vulnerable city before El Niño.
Cambiar a español | Go to El Niño | Go to Frontpage
By Julio ernesto Gianella*
All the images provided by the author*
March 27th, 2017's flood, there is the perception that Piura City's
rehabilitation and rebuilding works will not resist any rain season.
PIURA CITY, Peru -
The knowledge we have not assimilated from Pre-Hispanic people is the
urban planning. The best proof is that many of the cities built
in the past are still there despite the natural disasters
and the time lapse.
The city of Caral (Supe, Lima),
the most ancient of South America, was wisely built and it has not
suffered from floods , Nature's onslaugths neiter, in 5000 years
The virtue of
urban planning is upon the balance between the what we want and what we
can. If it has no contribution of the vision and the
wishhes on a better future, we stay trapped into more of the same; in
the other hand, if it exceeds in futurist dreams, it
crashes into the reality and detracts.
That is why the
main basis of the Piura's future planning must be the invulneribility
before the natural phenomena, and our operative guideline must be the
most rational use of the available resources, not wasting but
keeping the quality and the durability of the investment.
In the other hand, we have to keep in mind that the centralism in Peru
is the main cause of the secondary cities delaying. To realize that,
let's compare the five major cities of this country to Colombia's, taking a kind of closer example to understand how much back stepped-down we are: Lima to Bogotá, Arequipa to Medellín, Trujillo to Cali, Chiclayo to Barranquilla, and Piura to Cartagena de Indias.
The three main
cities in Peruvian Northern -Piura, Chiclayo and Trujillo- might target
to superate a million people each one, in 25 or 30 years up to come.
The population growth of Piura City is 3% annual in average - in 42
years it has gone paralell to a life quality deterioration.
Piura City grew aside so between 1970 to 2017.
The Urban Expansion of Piura
The Piura City's
Urban Development Plan (UDP) was formulated by the province's
municipality in 2014, with a 18-year horizon to 2032.
Although it is about a very well structured document, the following
questions on its insights are regarding:
- The predicted
total urban area seems to be quite exagerated, because it could suppose
to grow in 15 years more than four times the actual area.
- It does not
consider the potential of urban home growth towards the North in
direction of Piura-Sullana Axis (it only considers an industrial
- Piura will
require in an upcoming future a civic-financial center at a big
city scale, what I could not clearly identify in the plan.
- It keeps the
actual location of Castilla Airport: as it has limited to a 2,4 km or
1,5 miles lane, it can not reach the international
Between 1970 and
2017 the Piura City urban area increased almost 150% coming from
16 sq km or 6 sq mi to 24 sq km or 9 sq mi, what means that
population density (habitants per hectare or hab/ha) increased
from 80 hab/ha to 120 hab/ha (1 hectare equals 2,47 acres).
The areas of
major expansion potential are located to the East, in Castilla
(included in the UDP), and to the Northwest, in 26 de Octubre
(not included in the UDP). In both cases, they are about
relatively high lands with good drainage and easy access by
Pan-American and Interoceanic Highways.
The big limiting of the future urban expansion will be the availability of water sources for human consumption.
Why The City Flooded?
The easiest way
is blaming the river and its overloads, when the human being is the
main guilty who has modified and destroyed the natural
conditions of that. First of all,
the natural courses of the rivers must be respected and
conserved, and the overflows occured during the big overloads are
not ever negative (as the case of Nile River and the natural
fertilization of agricultural lands).
As the human
settlements look for being closer to the rivers, because the advantage
of water supply and communications feasibility, they make
the conflict between the protection of the habitat and the water free
In Piura City's
case, the 1588's primal settlement, just more than 40 hectares or 98,8
acres, was located on a promontory upon the Piura or Lengash River (6
meters or 20 feet above its dryness level), and historically it did not
suffered from significant floods until we have experienced
It also happens
that the human being has destroyed the vegetal cover at the highlands
of rivers' basins, modyfing the natural runoff what has increased
considerabily during the rain periods.
Thus, the historical situation of Piura River has changed due to the action of human being:
a) Because of the destruction of the forests covering totally the Andean Range's West slope, and;
b) Because of the course modification, mainly through the rims narrowing.
When The Drainage Is Dismissed
flooding Piura City every El Niño event has two different origins,
those require different type of forecast actions too: in one
side we have the water accumulating from the falling rain
directly over the urban area and surrounding mycro-basins, and in
the other side we have the water overflowing from Piura River
when the big overloads happen.
or 4-inch rain falling 10 continued hours, thing that is not rare if
happens, can cause more than 50 cubic meters per second or 13300
gallons per second of runoff across the whole urban area located on the
West Bank of Piura River (the primal Piura City, in other
Due to the
characteristics of roofs and pavements waterproff features, the
hydrographic of the runoff at urban areas modifies
evidently compared to the free land, increasing the peaks and
disminishing the period of runoff.
Every city in
the world built at geographic zones with medium to heavy intensity
rainsease systems of rain drainage with side diches,
drainss, or independent canals to waste water shewer, those lead in
major courses as rivers, lakes, or the sea.
Ath the Peruvian
Northern Coast, this practice have been lost under the though that a
heavy rain every decade (El Niño) would not be something to
concern about, avoiding the maximum cost.
It is necessary
to differentiate the urban mycro-drainage, aplied to areas until 100
hectares or 247,11 acres, from the urban macro-drainage, applied to
- The urban
mycro-drainage includes basically diches, drains, or conductive
irrigation diches, those carry continously the water by
gravity until the major system.
- The urban
macro-drainage includes natural creeks, those must be protected or
recuperated, and waterways built by the human being, that could be
zanjon-type (Sullana's case), or tunnel-shaped, or infiltration
These are the zones of Piura City with chances of flood from heavy rains or the Piura River's overflow.
Zone Assignment Before Vulnerability
2017 Coastal El
Niño confirmed the existence, inside Piura City limits, of
vulnerable urban zones what certainly will be
flooded by the future happening of that event, due to be at
levels below the river's overloads dimension.
with Changes Plan, it was chosen the relocation of that zones'
homes towards potentially non-vulnerable others as policy, which
implied the reservation, posession, and eventual expropiation of the
chosen lands for the moving, and the demolition and control of
the erradicated vulnerable areas.
Unfortunately there is a bit done about this sense, except the re-settlement of a part
of Lower Piura Valley's rural population (Catacaos). It remains
to solve urgently the problem of the settled population at
lowlands in the South (Piura) and the Southwest (26 de
Octubre) of the city, Gullman Avenue Axis' both sides, where it is
estimated 230 hectares or 0,88 square miles sould be
erradicated, relocating between 5000 to 8000 families.
zones of Piura City are located in the historic downton (critical zone
2), the Soouthwest exit (critical zone 1) and the portion of Castilla
City beside the Piura River (critical zone 3).
previous vulneribility analysis, the zones those would
deserve an attention as priority related to the
drainage and the potential of future floods are identified:
- Critical Zone 1:
Gullman Avenue Axis' both sides enlarging 2,8 km or 1,7 miles towards
the North from the crossroad with New Pan-American Highway. Human
settlements might be totally erradicated of a 230-hectare or
0,88-square-mile approximate surface .
- Critical Zone 2:
There is a natural land deppression located 500 meters or 0,31
miles to the West of the Main Square, which lowest part is
orientated along the axis descending from the North to the South.
Inside this deppression is Grau Club and its orientation coincides
muchly to Sullana Avenue Axis. Here we have favorable conditions for
easing a major structure belonging to the urban macro-drainage,
through what could be tasked to evacuate fastly the water in floods
case, rain origin and river's overflow as well, running the water
down to the South for draining into the Piura River's course, at
a point located in the dimension under the city level.
- Critical Zone 3:
Castilla District. A big part of the urban zone is below
the 30-meter or 99-feet altitude dimension and suffered from the
flood due to river overflow on March 27th, 2017. Although
there are protection dams on the river's rim, the problem
is, according to technical reports, those dams could contribute to
raise the dimension of the river's bed depth.
Piura, January 2018: Rehabilitated lane not considering rain diches and drains neither.
A good example
of rehabilitation work in the service lane at the auxiliar of North
Pan-American (Prolongation of Sánchez Cerro Ave.): Using
cobble pavement and side dich with discontinued rowlock.
How did the city response?
urban infrastructure -lanes, sidewalks, shewers- has collapsed
its big part. This situation is caused by the most of pavements
and wreckages built before 2017 el Niño event have not ccomplied
the quality standards, and tey did not consider the urban rain
works, it is necessary to measure carefully the benefits of an
inmediate rehabilitation with similar characteristics to what
tehre was, just in front of a superior quality, hig standards
rebuilding. If the resources are enough, it is clear the second
one is the choice we should take.
economic life practically begins with the building of the old
wood-&-iron bridge (Puente Viejo) in 1893, which lasted more
than a century.
The Piura City's Puente Viejo, in 1925.
In Piura's case,
the bridges play a fundamental role in the urban development. If it is
true the for existent ones for vehicles in the city area
have stood the big load of Piura River on March 27th, 2017, they
have not done the same efficiency. Cáceres Bridge (Cuarto Puente)
worked much more as a dam, increasing the overflow that finally
caused the flood of the city.
was concluded in 1995 not respecting rules of design,
narrowing the river's course by filling the river
platform that existed at the East Bank (Castilla). It is an
excess of supporting vertical structures (6) and its
flush is at the level of the streets to access to.
As a result, in
March 2017, it acted more like a dam instead of a bridge. As
appreciated dramatically on the photograph (excerpted from the
report of University of Piura's Institute of Hydraulics).
Agriculture Minister and the National Authority of Water's
director stated that "the non-mitigable high-risk
marginal zone (of the rivers) can not be occupied, so the
Pecsa Oil Station and Open Plaza's parking lot those
strangle Piura River's course by Cáceres Bridge must be removed,"
however long months have passed by and nothing of that was
In contrast to
Cáceres Bridge, the modern Bolognesi Bridge was concluded in 2001,
after 1998 El Niño, by using the best engineering, with a
big metallic arc 130 meters or 427 feet horizontal distance between the
supporting spots, without intermediate supports, what
beared the last overload without any problem, not interfering the
Bridge's cost, made-in-Peru steele structure, was about US$ 7
million of 2001, what considering the cost of living increase
(51%), might not be over about US$ 11 million.
Bridge, operating since 2001, replaces the one brought down by Piura
River during 1998 El Niño. It is a good example of engineering.
A Canal Way For Te Downtown
critical zone 2 previously quoted, it is located the core of the
major commercial, civic and cultural activity of the city, so it
deserves attention as priority for the purposes of urban planning and
drainage. The natural deppression regarding to this zone is
clearly delimited by the level curve related to 35 meters or 115
transversal diagram of the city's urban area (section in West-East
direction, 100 meters or 328 feet to the North of the Main
Square), the deppression is clearly visible, which lowest point
is 7 meters or 22 feet below the intersection point with
Tacna Street (calle Tacna), located to the East.
the deppression axis towards the North, going up Sullana Avenue, there
are favorable conditions for a major structure of urban
macro-drainage what could concentrate the evacuation of flood
water across approximately 10-square-kilometer or 4-square-mile
urban extension (almost 40% of actual area of the city in the
Piura River's West Bank).
macro-drainage could be 5,6 km or 3,5 miles length, could start at a
nearby point to intersection of San José María Escrivá
(prolongation of Sullana Avenue) and Educativa (prolongation of
Chulucanas Avenue) Avenues, near Los Jazmines Neighborhood, could run
down along Sullana Avenue Axis Northwest-Southeast direction until the
Sánchez Cerro Avenue intersection, then South course to Las
Palmeras Neighborhood, and finally Southeast course for leading
into the river.
It could start
at 41-meter or 135-feet altitude dimension and could finish
at 26,6-meter or 87-feet altitude dimension with a -0,27% average
This is The Way
Canal aligned to Sullana Avenue, in Piura City, that could prevent from
floods to its historical downtown, and could ease the transit flow.
also presents the opportunity to turn into a spped urban traffic car
way to be used everyday, every month and every year when
flood problems does not appear, as happened in Sullana with the Canal
Vía, built successfully after 1983 El Niño event, what works
perfectly only if keeping clean.
use of the macro-drainage canal for car transportation would
represent a significant contribution to Piura City's
modernization. In the intersection of the Sullana Avenue's Canal
Way andd Sánchez Cerro Avenue, that means the main khub of
the city, a by-pass bridge would be eased, what could relief the urban
The oxidation lagoons currently serving to Piura City.
waste water, located in the West Bank (not including Castilla) is
conducted and poured into the oxidation lagoons
located in the Southwest of the city.
have been largerly superated by the population growth and
are based upon an open-pit biological treatment technology, what
is not convenient for a city getting closer to the half-million people,
less still for the next 30 years, what is the horizon used
when projecting sanitarian works of that magnitude.
It is also
necessary to say those lagoons are inside the property of Kurt
Beer ecologic Municipal Park, what is a contradiction.
It is necessary
to project a new integral system of waste water conduction and
treatment by using modern technologies such as the
built ones in Lima (Taboada and La Chira) and Arequipa.
If we project
with Taboada Plant's costs, (about US$ 150 million of 2012),
designed to attend 8 million people, a plant for Piura
might not superate about US$ 15 million, plus the cost of the trunk
The new waste
water treatment plant for Piura should be located at enough distance
away from the city to avoid any environmental problem, and to the
South of course for allowing the conduction by gravity.
Now or never,
the rebuilding of the Peruvian Northern has to be boosted. The months
are running and the people waits for but also desperates about.
It is needed congruence (fruit of experience), urgency
sense (fruit of commitment), honesty (what nobody doubts
about), and a deep respect to the people (what could be lacking).
Architect. Based upon the presentation offered to the Inundación
Nunca Más Civile Association in Piura, February 8th, 2018. Additional
reports and writting by FACTORTIERRA.NET.
featured on this article were provided by the author not identifying
the source. If you believe those images belong to you, please notify us
at firstname.lastname@example.org to include the credit.
Thanks to Arturo Peñaherrera Castillo for collaborating to this article.
Explore more news and stories about community geography and El Niño.
© 2007-2018 Asociación Civil
Factor Tierra. All Rights
Reserved. Distributed Worldwide by