Recent content by gwool

I'm not sure how to model this situation and any help would be greatly appreciated: There is an old mill site having a weir, which is about 1.5 ft. high. Only about 10 ft. downstream of the weir is an 88" x 66" elliptical pipe that crosses under the road. I have figured out how much storage...

Is it ok to have to toggle between finer routing settings for different storm events? For example, I have the setting as 2 during the 10-year event but have to switch it to 3 for the 25-year event in order to not get the Qout > Qin warning message.

I'm not sure I follow what you mean by using a second culvert outlet if the storage is the same pool for both culverts... Thank you for your help once again!

I have a culvert that crosses a road on a slope, not at a low point in the road. Once the storage behind the culvert fills, any overflow will continue down the roadside ditch to another culvert. What's the best way to model this scenario? Right now I am using a very small broad-crested weir...

Thank you, psmart!

When using custom pond stage data to model a culvert crossing, is it necessary to enter an elevation higher than the top of the road to define overtopping? For example, if the elevation of the center of the road is 103.5, is it necessary to enter a value of say, 103.6, (accompanied by a very...

psmart - Thank you so much for all your help! I looked at adding back a shorter reach and it seemed almost trivial because the length would be so short ~ the inundation level behind the culvert extends for a considerable distance. I think I'll leave the model as is... I'll be sure to post my...

psmart - I just had one more question: I replaced the reach + pond/culvert with just the pond/culvert. It worked! I started thinking...isn't the travel time affected now? The reach I replaced was quite long - about 1000 ft. The travel time for the reach I removed was about 12 minutes. Is...

Great! Thank you!

Hi psmart - I think I understand what you're saying and it makes sense. The bottom line is that the reach upstream of the culvert is, by definition, under Manning's flow, whereas by adding a pond with culvert outlet I'm telling the model I don't WANT Manning's flow. To correct this I should...

Hi TerryScan - The 4th culvert empties into another smaller floodplain, which I have modeled as a Reach: L=335', s=.0031, trapezoidal channel 75' wide, 1' deep, side slopes 20/1. Again, these are existing conditions and everything seems to be working properly as-is, so I'm not sure what the...

Thank you again for your reply - The warning message is that the "culvert exceeds the reach inflow depth by 1.96 feet (warning message #63)." Should I model the culvert differently, or does my approach seem ok? Ultimately the problem is that a subdivision is planned for within this flood...

Thank you for your quick reply! The ultimate goal of this model is to determine (a) whether the existing culvert is appropriately sized or needs to be replaced with a larger one, and (b) to determine whether runoff will increase from pre-development to post-development conditions at the...

I have a situation in which each of 3 subcatchments drains through a respective culvert and into a 4th subcatchment, and then that 4th subcatchment drains through a 4th culvert. This 4th basin is a large flood plain and would fill in during larger events. When this happens, the "reach"...