EG
Civil/Environmental
- Mar 5, 2002
- 20
HI All,
We are assisting with a re-waterproofing project for an existing hotel plaza. There is an access road that comes spiraling down from the street and to a rather large plaza for guest arrival/check-in (all open air, above grade). This is a porte-cochere that is similar to a loop/cul-de-sac with a branch that leads down to an underground parking lot. The surface (landscaping areas, sidewalks, road, etc.) has had leakage issues develop over time and is going to be scraped, waterproofed, snowmelted, and re-surfaced. Very expensive.
There is a very limited amount of surface drainage facilities...a few small area drains (4" dia) and a couple trench drains. THERE ARE NO SURFACE OVERFLOW OPPORTUNITIES as the site is located in a 'hole' and there are no easements through the developed adjacent properties for introducing a new storm sewer. It appears that during a heavy rain, the trench drains wouldn't catch anywhere near the amount of runoff and that the drainage will continue down into the parking garage.
This is an older building and there are no plumbing drawings that have been found. My concerns are this:
1. If we analyze the drainage requirements and introduce new catchments, they will need to penetrate the structure/deck and tie into the existing drain system;
2. These new drains will certainly increase the amount of flow into the internal pipe system and we have no idea if there is adequate capacity;
3. The site improvements are basically going back in exactly where they were (same grades and alignments) so a substantially improved drainage concept can only occur through additional inlets (see #1 above)
4. The nature of the site crosses over thresholds of responsibility: From Civil (site/surface) to M/E/P (inside the building);
5. If we do nothing to improve the site drainage after recognizing the obvious deficiencies during a remodel (the best time to fix it), are we violating our duty and the Standard of Practice?
At this point, we have (in writing) asked the architect/project leader if there have been any drainage issues/complaints (they said there have not, but I doubt the question was posed to the hotel). I am leaning toward analyzing the existing drainage facilities to determine how much of a design storm (100 year?) can be collected with what is there now and how much is likely to overflow into the parking garage for the 'handoff' to the plumbing engineer...
Any advice is appreciated.
EG
We are assisting with a re-waterproofing project for an existing hotel plaza. There is an access road that comes spiraling down from the street and to a rather large plaza for guest arrival/check-in (all open air, above grade). This is a porte-cochere that is similar to a loop/cul-de-sac with a branch that leads down to an underground parking lot. The surface (landscaping areas, sidewalks, road, etc.) has had leakage issues develop over time and is going to be scraped, waterproofed, snowmelted, and re-surfaced. Very expensive.
There is a very limited amount of surface drainage facilities...a few small area drains (4" dia) and a couple trench drains. THERE ARE NO SURFACE OVERFLOW OPPORTUNITIES as the site is located in a 'hole' and there are no easements through the developed adjacent properties for introducing a new storm sewer. It appears that during a heavy rain, the trench drains wouldn't catch anywhere near the amount of runoff and that the drainage will continue down into the parking garage.
This is an older building and there are no plumbing drawings that have been found. My concerns are this:
1. If we analyze the drainage requirements and introduce new catchments, they will need to penetrate the structure/deck and tie into the existing drain system;
2. These new drains will certainly increase the amount of flow into the internal pipe system and we have no idea if there is adequate capacity;
3. The site improvements are basically going back in exactly where they were (same grades and alignments) so a substantially improved drainage concept can only occur through additional inlets (see #1 above)
4. The nature of the site crosses over thresholds of responsibility: From Civil (site/surface) to M/E/P (inside the building);
5. If we do nothing to improve the site drainage after recognizing the obvious deficiencies during a remodel (the best time to fix it), are we violating our duty and the Standard of Practice?
At this point, we have (in writing) asked the architect/project leader if there have been any drainage issues/complaints (they said there have not, but I doubt the question was posed to the hotel). I am leaning toward analyzing the existing drainage facilities to determine how much of a design storm (100 year?) can be collected with what is there now and how much is likely to overflow into the parking garage for the 'handoff' to the plumbing engineer...
Any advice is appreciated.
EG
