May 2003 Drainage Report

I promised Joe that I’d stick to facts in my presentation and try to avoid engaging in speculation. Even though I live on the ocean side, I’ve spent a good deal of time this past winter wandering the pine side drainage ditches with a rake, shovel and 12’ long bamboo pole. Sometimes also with a clipboard and a pencil. I figured that in the 12 years I’ve been a member of this community, I’ve spent about 8 hours at Annual Meetings listening to people talk about drainage. In order to avoid spending the equivalent of another few days of my life listenting to this, I figured it should be worth some of my time examining the problem first hand.

If you haven’t been around for past meetings, let me summarize the last 35 years: the pine side drainage system is composed of 11 drainage ditches-2 on each side of each road, and one on Evergreen Road. Some of the ditches are entirely on private property; some of them are entirely on MBA property, and some of them straddle the property lines. For reference-keep in mind that utility poles are usually within a foot of the actual property line. 5 of the ditches (Evergreen/Addy/Bridge) drain past the tennis courts, through a stream under some houses in the Cat Hill portion of South Bethany, and then into the Assawoman Canal. The other 6 ditches feed into a main ditch along the east side of Kent Avenue behind us, crosses under Kent Ave, and eventually disappears into the wetlands adjacent to the Assawoman Canal. So effectively, we have 2 unconnected drainage systems in the pine side. These ditches to our west are themselves frequently full of water so there’s no place for our water to flow; the ditches in front of each property on the pine side are frequently full of debris (both living plants and dead debris) which slows both drainage in the downstream direction and percolation of water into the soil; and many driveway culverts are either completely jammed up with debris, slope the wrong way, or are located at an improper height relative to adjacent culverts.

Heights above sea level are routinely measured from what the USGS calls “Mean Lower Low Sea Level. On the beach, normal tide swings are usually between 0 feet at low tide and 2 feet at high tide. The USGS has a tide gauge where the South Bethany Canals feed into the Assawoman Canal/Bay. It’s available live on the internet, and shows that the water level usually ranges from about half a foot above MLLSL to about 1 ½ feet.

We have a copy of the surveys done by Artesian water in 2000 which precisely locate the elevations of several of the main culverts along Kent Avenue to our west. Most of these culverts are situated within one foot of the canal’s high tide. We also have some surveys of the community done in 1992 by the Delaware Soil Conservation people-these locate almost all driveway culverts in existence at that time. While many driveway culverts have been replaced and moved since then, it is nonetheless a useful set of numbers. This information, when correlated with the Artesian survey, shows that some of our driveway culverts are actually located below the canal’s high tide. So here’s another fact: if the ditches “downstream” of us were completely cleared by the state (ignoring the fact that there are protected wetlands which cannot be touched), we would have tidal swings in some of our ditches. Every day. The fact that these ditches are very jammed up is what keeps this from happening.

Last August, several of us met with Mike Henry of DelDOT, and he promised to have the Kent Ave ditches cleared out for us. They did this in April, and also replaced several culverts on the west side of Addy Road (at a Sea Colony driveway, and at a Conectiv Power Station driveway). They had intended to put in a culvert that would connect our 2 drainage basins, but Miss Utility put so many marks on the ground on the east side of Kent Ave that DelDOT decided it was too costly to get involved in that.

Also, just within the past week, we’ve obtained the name of the official in DNREC’s Drainage section-Bob Long-and we’ll be checking with him to see what they can do for us.

In March, several of us met with Chuck Hauser of Davis, Bowen and Friedel, which is a reasonably large engineering firm on the eastern shore, and has done extensive drainage work in the town of Bethany Beach. He had a decent background on our layout because he’d done extensive research on the middlesexbeach.org website. They got back to us in April with a detailed proposal of how much it would cost to do a more accurate study of elevations, soil conditions, and after coordinating with various state agencies, provide us with a list of improvements and estimated costs. This proposal is for far more than had been budgeted for drainage this fiscal year.

Another fact: according to the national Weather Service and the US Geological Survey, the snowy and rainy winter we just endured has officially brought the east coast drought to an end. That, and the fact that in Decmeber one homeowner had a burst water pipe that ran for over 24 hours, left us with a phenomenal amount of standing water, particularly on the block between Addy and Bridge Roads. While I wouldn’t advise that everyone try this, it did make it quite evident that a clogged culvert under one driveway can dramatically affect their neighbors ability to walk into their front door without putting on boots.

Our restrictive covenant #11 states in part, 'Each property owner shall maintain the drainage ditches which are contiguous to his property in proper grade and proper flow to permit free flow of drainage waters (to prevent stagnation and unsightly and/or unsanitary conditions as determined by Middlesex Beach Association). If any property owner fails to fulfill any of the requirements of this covenant, Middlesex Beach Association may, after due notice, correct the condition at the sole expense of the property owner in a manner as determined by Middlesex Beach Association."

Back in 1991, a letter was sent to all homeowners reminding them of this covenant, and requiring that all ditches and culverts be made “free flowing”. From what I’ve learned from the person who thinks he wrote it, this led to discussions between accountants of how much this work should cost, the manner of providing the due notice, and the legality of, in effect, assessing some properties at a higher rate than others. And of course, others argued the precise meaning of “proper grade and proper flow”.

Here’s another fact: if the water level in the ditch on one side of your driveway is 1 feet higher than the water level on the other side of your driveway, and it’s been that way for a month, your culvert is NOT free flowing.

So back to the facts: all discussions I’ve researched, by experts and amateurs, lead to the statement “try actually maintaining your current system for awhile and see what happens.” So, in that spirit, I’ve spent most weekends in March and April wandering the ditches with various tools (and Joe Wolf’s hip boots have helped enormously) stuffing my 12’ bamboo pole through culverts in attempts to get water flowing better, and raking piles of debris out of various ditches wherever I see the least little bit of obstruction. I will add that I’ve waded all the way downstream of us –that is past the tennis courts and into Cat Hill- to see what else is there, and how the drainage water from our neighbors ties in with the same system we use, and if somehow the culverts leading out of Bahama Beach Cottages accidentally got blocked so that more of our water could get to the canal, I’m truly sorry.

So-we’re stuck with the fact that the entire pine side is within 10 feet of sea level, and that our water doesn’t have much of anywhere to go. Having never seen the current system being properly maintained, it is a fact that I’d favor actually doing that for the next year or so. The proposed budget does include drainage maintenance funds, so the Public Works Committee will need to decide the best usage for these funds. We’ve talked about doing one street at a time, or one block at a time, but I think it’s best to focus on just the last 3-4 properties on each street.

I will note that the basic options likely to be presented by DB&F (or amateurs with Civil Engineering degrees like myself) fall into 2 main categories: one is a gravity flow system-basically what we have now, but with properly situated driveway culverts, and ditch bottoms. The other main option would be a system with pumps. Due to the way the current ditch system is laid out, it would be much easier to locate pumps to drain the southern portion of the pine side than the northern portion. In either case, the driveway culverts could be connected either by open ditches or by buried culverts with catch basins. Buried culverts have some attractions, but keeping them properly maintained would be more costly than maintaining open ditches. In Bethany, several of their recently buried culverts are more than half filled with sand. Another option that’s been suggested in the past is the use of French Drains-basically deep holes filled with rocks and gravel so that water can percolate into the soil easier.

Something else we need to keep in mind is that some homeowners have extensively landscaped around their driveway culverts. If it’s just a stone or concrete wall on top of a culvert, it obviously doesn’t restrict water flow until it crumbles and falls into the ditch. If it’s covered with ivy, you really should clear that away, without waiting for someone to specifically suggest that you do that. If the driveway culverts were to be connected by buried culverts with catch basins for surface water, then there would be no need for that concrete retaining wall, and the driveway culvert could be raised or lowered as necessary to conform to the overall plan. However, if we elect to stick with open ditches, then I’d hate to think we’d need to tear out extensive landscaping just to move a culvert by a few inches.

If the Dutch can keep dry, we could also. The question to be answered is “what’s the cost, and will it provide enough of a difference to be worth it?”