A Little Overdue, but still Ongoing
November 2012
Several of us traveled to Haiti in mid October to review the damage caused by Hurricane Isaac that passed over Haiti in late August. In general, the whole country took a medium beating from the storm, with some roads washed out, crops ruined, houses damaged, etc. The roads leading to our project had some damage as well, although by the time we arrived the road department had repaired the main road. The side road that leads through several villages to our site had been repaired enough by locals that we were able to get through in low range 4X4 with a spotter guiding us through the rough parts.
What we found wasn't a surprise to us, because it had been described to us by several visitors just after the storm. The canal has some damage, with about 15' of the wall broken away in one point, and some erosion undercutting the floor. One of our control gates has broken away (parts of it were found about 3 1/2 miles downstream). We found large rocks, some as big as basketballs, that had washed over the control gates, and partially filled the canal beyond. We estimate that 50 yards of debris were washed over the top of the ±4' high gates - it's hard to imagine the turbulent water required to move that size of rocks over that high of a wall. The gates are pretty scarred, but still very usable. We expect the canal repairs can be done in a week or less, and in doing so, we will reinforce some areas for future storm resistance.
The erosion at the dam site is more spectacular. What we call the dam is really a retaining wall that crosses the river just downstream of the entrance to the canal. During construction we were able to locate bedrock on the river bank nearest the canal, and a knob about 2/3 of the way across the riverbed to anchor the dam to, but in between those two bedrock points we dug down about 12' with the excavator, and didn't hit anything solid. We decided that that 12' was about the maximum depth that we could open and dewater a hole for construction, so without bedrock in between we built a dam to span the river. It is 18' high, and when it was finished we backfilled it, which raised the level of the river bed and created a waterfall. The height of the dam is such that water runs around the end of it until the desired high water level in the canal, at which time excess water spills over the dam. To reduce erosion, we piled many tons of boulders at the base of the dam to form a splash pad. We moved in all the big rocks from the canyon below -everything we could dig up and move in with a Cat 320 excavator.
Based on the water mark evidence on the canal walls, it looks like the water came over the dam 4 ' to 5' deep. The entire boulder field was washed away, and not to be seen anywhere in the river bed downstream. It appears that once the erosion protection was gone, the falling water undercut the dam until the backfill from the upstream side started washing under the dam, and about 2/3 of the backfill placed in 2011 was gone. The stream ran just under the dam in two places, with about 2' of clearance in the deepest channel.
We spent a number of hours poking, prodding, measuring, debating, and calculating. By the end of three days, we had come up with a proposed soil stabilization method, a way to re-backfill the dam, and plans for repairing the canal and other miscellaneous damage, including to the two fountains we had placed in several nearby villages. We also spent some time in Port au Prince determining the availability and pricing of materials, we looked for another vehicle to purchase, and made general plans.
As we left the country October 24th, all eyes were starting to look south, where another hurricane was quickly forming. When Sandy crossed over Cuba as a Category 2 hurricane, the storm was big enough that is was raining all the way from Venezuela to Florida, and was certainly raining hard in most of Haiti. According to most of the people we have had contact with there, it was the worst rainfall event in many years. At our congregation in Oriani, it rained for 43 hours straight, during which time they received about 2.5' of water! Houses, crops, roads, bridges, and people's hopes were washed away all around the country. We all have heard about and seen the immense damage caused when Sandy hit New York - at which time it was "only" a Category 1 hurricane. Can anybody imagine the damage if it was a Cat 2 when it hit?
When our local inspectors finally were able to hike back into the canyon to inspect (much more road damage than before), they were all concerned that this storm might have been the water that broke the dam, but to their amazement they found the riverbed was scoured down to bedrock for some distance both upstream and downstream from the dam, I mean bridge. It is now "high and dry" with enough clearance underneath to drive heavy equipment through! The water was still rushing down the channel, but the opening down to bedrock is about 45' wide at the top, 25' wide at the bottom, and about 15' high.
We have enough data points from 500' upstream of the dam to about 3/4 of a mile below the dam to calculate the average change in river bottom to be about 18'. This means that in this 3/4 mile area, 18' deep X the average riverbed width, approximately 500,000 yards of material were washed away. And it didn't just was around the next corner - 3 1/2 miles downstream the river bed is down about 4', and along the way it widened the river about 75' through one village for about 1/2 mile, washing away to within about 3' of the nearest house, and made sundry other adjustments to the landscaping! This rock was deposited after the river slowed down as it widens out into the farming valley another mile or so downstream. Some of it washed an additional 2 - 2 1/2 miles and buried a few fields that were getting irrigation water from our system.
We don’t view the altered landscape at our dam site as a huge disaster, but rather it's really a blessing. We had debated the idea of excavating down until we found solid rock, but had ruled it out as to much overburden to move with the equipment, time, and space we had available With the bedrock exposed, we can construct under the dam/bridge down to it, and eliminate the problem of future erosion. We estimate it will take an additional 170 yards of concrete, and increase the height of the dam to 33'. I have been working with local engineering firm to come up with a plan to anchor this larger structure to the bedrock. Since we still have our rock drill there, we will drill anchor holes into the bedrock as part of that plan.
With our options narrowed down to just one feasible way to repair the damage, our plans have been advancing. Nobody involved thinks we should stop working now, so we plan to resume our work in mid January. Most of the same core team will return, and we expect construction to last somewhere from six to eight weeks. We have been assembling tools and supplies on the east coast, and that container should ship any day.
As most of you know, an old Haiti hand Raymond Withers has been helping us in the past. We have used a lot of his machinery, tools, vehicles, and expertise on this project. Last year he was laid up in Texas recovering from a surgery, but we had his dozer, pickup, quad, welder/generator, misc tools, and his hired man helping on our project! This year he plans to be building a bridge about five hrs drive to the west, and of course will be using all of his resources there. We are faced with ramping up our current transportation fleet of one pickup to at least one more vehicle, and at least one quad/ATV. We found and purchased a 1999 Arctic Cat quad; Sam has gone over it stem to stern, and almost $2000 worth of parts has shipped by air to rebuild it. That seems like a LOT of money to spend on a machine that is that old, but it has one major thing going for it - it's in the country with all the taxes paid! It is incredibly difficult and time consuming to import any motorized piece of equipment into Haiti, and we felt that this one was the most time, cost, and stress effective way to go. It's also the only utility/work quad I have ever seen for sale in Haiti - mostly we see sport type machines that the really rich people use for toys. The above mentioned container has a welder, cutting torch, shop tools, tires, and other stuff needed on board, as well as some supplies for some of the other mission efforts of the church in Haiti.
As mentioned above, some of our previous workers plan to return, but at this time we still have openings for mechanics, equipment operators, and concrete contractors, as well as general help. If you have an interest in putting in some time, contact Roger Jantz or Kevin Bronson for details on the openings and skills we're looking for.
In additional to the canal re-building project, we have also been forming a Water Committee to manager the distribution of water, and to maintain the canals in the valley. Slightly over 1200 farms receive water, and they have agreed to pay for the water to fund system maintenance and improvement, and asked us to provide that information. The agreed upon rates are based on the area of each farm, so we are mapping and calculating the area as part of this process. We have committed to having this mapping done, and issuing a "water rights certificate" for each farm when we return in early January. The CPS Unit in Haiti did the mapping field work in May of this year as one of their last major projects before the Unit closed. All that is left to do is the drafting & calculations, which have proven to be quite time consuming. If somebody with AutoCAD drafting experience has some time to volunteer for this project, it would be much appreciated. Please contact Kevin Bronson for details.
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