LLV Engr

Hydrology

Thought I'd take this to your talk page. What is the white structure we're seeing through the Lake Las Vegas dam in this picture? I've been looking at Google aerials to try and find the components that are visible to figure out how this all worked. You can trace the LVW to LLV Parkway where you see an intake structure; you also see a spillway which looks to be built under the Parkway; I assume this is for flood waters. On the dam side, I see a big pipe that comes out under some property occupied by the Mantova Condominiums; and then just under the dam you see and outlet structure. What are these two structures and how do they relate to the picture you posted from 1991 showing the structure through the dam? Finally, there looks to be a small spillway at the very northern extremity of the lake that looks like it could be used to funnel overflows down to the LVW. I just noticed this. Could you describe how all of this works? Criticalthinker (talk) 09:23, 11 December 2023 (UTC)

Good questions and observations!

The white structure is the primary spillway inlet with a channel to the LVW. There are two more spillways on the dam on the north side. The one under the bridge is the auxilliary spillway abd then there is the emergency spillway. The primary and auxilliary spillways have been utilized but the emergency spillway has been dry so far.

At the west end there is an intake structure with control valves diverting LVW into two 84" pipes. There is also a spillway from the LVW into LLV as you noted. That spillway into LLV has been used a lot!

Have you ever visited LLV? LLV Engr (talk) 02:28, 13 December 2023 (UTC)

I have. My dad took me out there in the late 90's/early 00's as a child to see them working on the projects.

Looking back at the aerial, I just realized that primary (outlet) spillway is visible in the current Google aerials of the lake. Right next (west) to it is the large-diameter pipe I mentioned. It's outlet is visibly lower in elevation than the end of the concrete spillway you can see peeking out through a smaller culvert. What is this structure? And then west of that and lower still appears to be the outlet for the Las Vegas Wash. And, yes, I can now make out on the aerials the secondary spillway (furthest north), and then the emergency spillway (immediately south of that), which is much very large. I guess I hadn't even considered that Lake Las Vegas Parkway over the dam is literally part of the spillway unlike on the other side of the lake where the spillway is beneath the parkway. Anyway, looks like I've got most of this down save for that part of the structure on the south end of the dam where the primary spillway is. Criticalthinker (talk) 10:46, 20 December 2023 (UTC)

Got around to mocking up a Google image showing what we're talking about to help with this.

https://imgur.com/q3wOqpw

"P" is for the primary spillway, "E" is for emergency, and "A" is for auxillary. Are these labeled correctly? And then the final "???" is what I was talking about. What is that pipe? Criticalthinker (talk) 04:59, 28 December 2023 (UTC)

??? is the outlet of the "Horseshoe Conduit". That is where the two 84" pipes go through the dam to discharge the LV Wash flows back into the wash. The pipes transition into the structure. The Lake Drain also goes into the structure. LLV Engr (talk) 05:13, 28 December 2023 (UTC)

Thanks, so then what's the area I have labeled "LV Wash" and what is the use of the "Lake Drain" if there are already three other spillways? I was under the impression that what I have marked as "LV Wash" was the outlet for the two concrete pipes. Criticalthinker (talk) 05:44, 28 December 2023 (UTC)

The problem is that your photo is of the dam under construction. During that time, all 3 spillways were not completed and the horseshoe conduit was also still under construction, I think. Not sure of the date of that photo, and I am not sure but one of the wash flows might be the temporary bypass for construction

Is there a way I can email you directly? I can send other photos that way. LLV Engr (talk) 16:08, 28 December 2023 (UTC)

The photograph I marked up and uploaded to Imgur and linked you to is a Google Earth aerial dated from this year, so this shouldn't be an issue; any construction you see in those aerials is unrelated to the Wash or dam. I will look to see if Wiki allows users to email others without having to post their email addresses, as I'm not comfortable posting it on Wiki. It you have another website or something where I could contact you, I'd be okay doing that. All that said, I've got everything marked up on the photo I linked you to. Where I have marked up "LV Wash" is where I thought the two pipes for the Wash outlet. If it, in fact, outlets from the single pipe I marked with "???" then what is the outlet I have marked as LV Wash? Criticalthinker (talk) 08:12, 29 December 2023 (UTC)

Eh, I figured this out with help from someone else. In my marked-up aerial graphic, what I have marked as "P" isn't actually anything related to the water works. I was kind of skeptical, myself, but it appears to be a concrete structure like the historic aerial shows. "P" should be where "???" is on my marked-up graphic, as it's the primary spillway and lake outlet/drain. So that solves everything. Criticalthinker (talk) 08:24, 20 January 2024 (UTC)

Nice detective work! I will look through my files and see if I still have the plans. I am not as tech savvy as you so any suggestions on how I could make those available? If you live in the area, perhaps we could meet and I can hand you a thumb drive? LLV Engr (talk) 16:54, 20 January 2024 (UTC)

To upload images to share, you could try Imgur or Flickr. To upload and share a bit of everything - all kinds of file formats - you could try Microsoft Outlook's OneDrive or Google Drive. All of these, of course, would require you to sign up an account for them to use, but they are all free. And if you already have a Microsoft, Outlook, Google, etc. account, then you simply sign in. BTW, no, I do not live out that way, but am familiar with it from having family who lived there for some time. Criticalthinker (talk) 15:15, 23 January 2024 (UTC)

I am a volunteer with NASA's solar system Ambassador program through JPL. You can look me up there and send me an email using the NASA address. If you provide your email in that email I can then email you directly without making either of our info public.... Steve Ainsworth LLV Engr (talk) 00:00, 1 February 2024 (UTC)